Came back to MHW on PC for Iceborne, so far not much seems to have changed for IG important new kinsect mechanic (that's explained nowhere but the Hunter's Notes)! See below.

Keep in mind you can claw grapple from the air by using your slinger keybind; it's difficult to aim for a specific part this way though. Claw grappling doesn't seem to interfere with mounting so don't let that keep you from trying intermittently. Mounting is very important now that flashes have limited value in MR.

New aerial attack! At least I think it's new, I totally missed it pre-Iceborne if it's not. [Q] in the air does a dragoon spike landing attack followed by a horizontal swing that target marks for your kinsect, so there's an extra option for the air and for getting your bug into the fight.

Press [P]+[S] while aiming your kinsect to supercharge it using your equipped slinger ammo. There are two variations: Power (red icon), using slinger ammo acquired from monsters, and Spirit (orange icon), using slinger ammo found around the field. Both allow your kinsect to store 2 buffs instead of 1 for faster buff collection.

Kinsect Charge (Power) increases the insect's damage and decreases the interval for it to spread dust effects. Kinsect Charge (Spirit) increases the insect's maximum stamina and increases the duration of the buff effect it gives you!

The charge seems to last quite a while The red charge lasts quite a while but the orange charge doesn't last very long so it's kind of a toss-up which to prefer. Both don't use up much slinger ammo so either is an essential new part of your combat strategy. Using the claw to weaken parts is also new and essential but most weapons are going to be doing that as well. Individual parts seem to need about 4 hits to become weakened, [S]>[S]>[S]>[P] while grappled will ensure it in most cases--if you can hold on long enough.

This is a quick guide on what to do with your insect glaive once you're in combat. I won't be covering builds, specific weapon or insect choices, or general basics for combat. Full disclosure: the content here isn't based on any deliberate optimization, but it's pulled from a combination of tips and advice I've gleaned elsewhere and a ton of personal experience using insect glaive.

I'm going to use some non-traditional references to buttons to accommodate all potential keybind layouts or controller setups, listed here:

[P]: for Primary attack, listed as "Normal Attack" in keybinds (ie the button that draws your weapon)

[S]: for Secondary attack, listed as "Special Attack"

[Q]: for Unique attack (for insect glaive this typically is for attacks that involve the insect)

↑ denotes forward, ↓ denotes backwards

> will be used to indicate button transitions for combos

• [Q] without weapon drawn draws your weapon and sends the insect out in a straight line forward from your character.
  
• The "Drawn: Aim Weapon" keybind allows you to aim your insect while your weapon is drawn, it can be set the same as or separate from slinger aiming.
  
• [P] while aiming sends the insect to where you're aiming; [S] calls it back and gives you any buffs it's carrying.
  
  
• Important: The insect has stamina that depletes any time it's sent out, however manually recalling the insect restores a chunk of stamina. You can easily abuse this to restore stamina significantly faster than it regenerates naturally by aiming at the ground next to you or close-by targets to minimize travel time.
  
  
• Spamming insect attacks manually can be a useful source of low but easy and safe damage and can be used to stop fleeing monsters.

• Press [P]+[S] while aiming your kinsect to supercharge it using your equipped slinger ammo.
  
  
• There are two variations:
  
  • Kinsect Charge (Power) - Red icon: Using slinger ammo acquired from monsters, increases the insect's damage and decreases the interval for it to spread dust effects.
    
  • Kinsect Charge (Spirit) - Orange icon: Using slinger ammo found around the field, increases the insect's maximum stamina and increases the duration of the buff effect it gives you!
    
  • Power has a longer duration and Spirit has a shorter duration, however Spirit also fully fills your insect's stamina so I would suggest using orange as long as you can remember to rebuff periodically--in most situations it's easy to grab a stack of 20+ stone at the start of a hunt and rebuff any time you notice the insect's stamina getting below about half (assuming you're deploying it constantly, which you should).
  
  
• Both variations allow your insect to hold 2 buffs at a time!

• The first thing you need to do when you get into combat is use your insect to buff up. Insect buffs in order of importance are:
  
  Red - improved attacks
  White - faster movement
  Orange - knockback prevention while attacking
  
  
• Knowing which parts of monsters give which buffs is a matter of experience; in general Red comes from the monsters head or primary offensive parts (eg Odogaron's claws, Diablos' tail club), White often comes from the main body or wings of the monster, and Orange typically comes from limbs or tails (if they don't give Green). There are a number of notable exceptions, especially where White and Orange or sort of inverted, but they'll come with experience. Green, if available, is virtually always the tail.
  
  
• Buffs refresh as more are added and are augmented as more are added (eg Red+White gives even more +offense than Red alone), so for example if you can quickly get Red and White, which are both essential in all situations, you can hold off on Orange until some time has passed to refresh the buffs duration.

• [Q] with weapon drawn or while aiming with weapon drawn marks the target by melee attack and projectile respectively. This does two important things: adds more autonomous damage and allows your insect to spread its dust effect. Dust effects are activated by any attack that hits them.
  
  
• Any time you're repositioning, take a moment to look at your insect's stamina to see if you need to take a moment to recall for stamina restoration or reset Kinsect Charge (Spirit).

As mentioned above: the first thing you need to do when you get into combat is use your insect to buff up. You want to have Red buff at minimum before you start trying to do damage. Buffing quickly takes practice and is naturally going to be much harder with a controller but it's essential to staying sane with your insect glaive.

Even more terminology! Here are most of the important ones you'll want to know:

• Rising Slash Combo ([RSC]) - a series of 3 vertical clashes; neutral [P]
  
• Wide Sweep ([WS]) - neutral [S]
  
• Tornado Slash ([TS]) - a big leaping double hit for big damage, moves you forward; eg the second attack of [S]>[P] or [P]>[P], Tornado Slash is only available with Red buff (non-Red version is Overhead Smash)
  
• Thrust ([T]) - [↑P], also comes out if you [P] from a roll as well as at various points in combos
  
• Leaping Slash ([LS]) - a forward twisting slash attack, moves you forward; [↑P] without weapon drawn, [↑S] with weapon drawn, comes out if you [S] from roll
  
• Dodge Slash ([DS]) - a backwards spinning slash attack, moves you backwards; [↓S] following most other attacks
  
• Kinsect Mark Target ([Q]) - a single weak horizontal slash that marks the target but also combos from just about everything

• In general, your goal is to Tornado Slash as often as possible for big damage and there's a number of ways to get there:
  
  • [RSC]>[TS] ([P]>[S]) is probably the best, RSC's 3 hits is slightly superior to [WS]'s 2
    
  • [WS]>[TS] ([S]>[S]) will also get you there
    
  • Learn to recognize what Thrust, Leaping Slash, and Rising Slash Combo all look like so even if you don't memorize the combos you can know how to get to Tornado Slash from there.
    
    • [T]>[WS]>[TS] (eg after a roll)
      
    • [T]>[DS]>[TS] (if you need to reposition backwards)
      
    • [LS]>[TS] (to draw weapon or after roll, can also [LS]>[RSC]>[TS], good for tail hits)
  • [TS] combos into [T] or [Q], so keep that combo going!
    
  • [TS] throws you pretty far forward so a lot of this is learning what attacks help you reposition or when to just roll out and reposition manually.
• There are several infinite combos that make for great sustained damage:
  
  • [S]>[S]>[P]>etc is my personal favorite since it includes [TS], but may require occasional repositioning
    
  • [P]>[P]>[S]>etc is the classic, good for when you need to avoid having to reposition and the first two attacks have great vertical reach; technically, if all hits land this combo does more damage than the other one
    
  • Several combos that would normally just end can be combo'd into [Q] which itself goes directly into [RSC] AND [WS] and let you continue on. The drawback to extending combos this way is that it's a weak single hit that doesn't benefit from Red buff changing the moveset.
    
  • Dodge canceling anything is always an option and goes directly into [T] and [LS] as well. There's a limited ability to change direction from roll with attacks as well.

Generally, engaging exclusively in aerial combat is going to be less damage over time than the above, but it's very useful for positioning, dodging horizontally oriented attacks (especially flame breaths), and mounting monsters from flat terrain. Some monsters, especially very large ones like Xeno'jiiva and Kulve Taroth but also some smaller ones, are safer to engage in the air at times. Aerial attacks also apply elemental effects at a reduced rate.

In Master Rank, mounting becomes very important both for giving teammates opportunities for claw attacks and for grounding flying monsters--since flashes in MR lose effectiveness very fast. I may be imagining this but it seems like monsters in MR have a shorter interval/stamina before they can be mounted again, and in my experience so far it's been worth attempting to mount every time a monster takes to the air.

The aerial [Q] attack is actually pretty good damage and isn't difficult to use at range so I find it's a good way to safely get in close in many situations.