Movement Stuff

In general: KEEP MOVING.
If you stay still or get cornered, you're done.

You run faster with the knife out (Default Keybind: 3)!

You can be EVEN faster by sliding and jumping right as you slow down from the slide.
You will see Players do it all the time. If you're familiar with Warframe or Apex, you know this :)

Sliding down slopes extends your slide all the way down. Works on stairs, too.

Ziplines can be life savers.

Shop

You can buy weapons from other Perks (Classes).
Inside the Shop checkout the Buttons on top.
Giga Tip: You can get the Medic's Pistol. It's Secondary Fire (Default Keybind: Middle Mouse Button) shoots Healing darts that resplenish over time. Very handy!
This also means, the Perk you wanna Level based on their Skill Tree and Gadget and not necessarily based on their weapons.

You can shop during a wave!
If you're in bad shape, you can hold the Highlight Button (Default Keybind: F) to find the next shop. Hold E on the Shop to receive some supplies immediately (gives Health, too!).

There is a limited supply of Tools (like Traps and Syringe Bags) for the whole Squad. Once it's out, it's out. Happens a lot with Ammo Caches.

Other Stuff

In the Stronghold (Base) you don't have to go to each station to access menus. Just press Tab :)

Check the Codex! It explains most things. Especially check Damage Types.

You can upgrade Weapon Mods!
Klick on a weapon, Klick the Slot (not Craft) and right Click a Mod you have. Some players did not find this and it makes a HUGE difference in Power.