This is an expanded version of the "cheat sheet" I used to narrate my video guide for city settlement in Illyriad.

First - always check with your alliance first. They may have alliance specific information or spots that will be very useful. Otherwise, continue:

City location checklist

• Settle in or near (within 200 tiles) an existing alliance cluster.
  
• Make sure that you have 1-3 high food tiles within 2 tiles of your city.
  
• Do not settle adjacent to Large hills, mountains or buildings. Settle next to forests only if you are sure at an alliance level that it is a viable option.

City tile checklist

• Always settle on a 7 food spot.
  
• Take 3 resource plots of the resource type you don't need for the unit maintenance reduction building. Unless you are building infantry 3 stone will usually be fine.
  
• You can settle on 5 or 6 food spots, this is usually for military accounts and should not be done without receiving advice.
  
• Settling on anything other than a 7 food spot potentially hinders your ability to grow past 10 cities.

Tenaril spell

• Allows you to instantly teleport a city from one location to another.
  
• It is located under the Castle/Relocation tab.
  
• The Tenaril spell also brings the underlying resource distribution of the starting tile with it, over--riding the resource distribution of the tile you're moving onto.
  
• It is very useful if you want to get to the Broken Lands quickly.
  
• You only have one spell per account.
  
• As you can have a second account it is a common practice to have one main account and the second count is used to get a second Tenaril spell. Once it's used its Tenaril spell it is abandoned and a new account is started. Provided you never have more than two accounts active at one time, you are within the game rules. Be careful not to use your referral link when creating your alt account.
  
• Can typically be purchased for 25 million. Ask in Global Chat.

Next city?

• Start looking to capture your 3rd, and if not that then definitely your 4th city.
  
• Although this is not always possible you should be actively engaged in seeking out a city to capture. Seek advice from your alliance to do so.
  
• To research the correct technology to capture a city you'll need a level 20 barracks. This requires a substantial amount of resources and will require (probably) more help than GC will ordinarily provide. Also note that it is low pop building so cannot be relied upon to increase your population to the next tier.
  
• When exodusing a city (after having research the tech unlocked by having a level 20 warehouse) consider delaying an exodus until you have captured your next city. Exodusing a city reduces your population as all building levels drop to 12. Additionally, your city is not counted towards your total population while it is being exodused. An exodus can take weeks, especially if moving to the Broken Lands.