I read an article about thinking about aspects over on Red Dice Dairies. It is something I didn't think about until recently. People have trouble thinking about an aspect if they have a free slot. He proposes a small questionnaire of questions relevant to the current game. I brought up having a pool of questions and players get to pick which ones. This helps with aspect creating and keeping the aspects relevant to the story. You could start with some generic questions to add to your pool and then add in some more specific questions related to the game. Here are some examples.
What was your upbringing like?
Who were your closest loved ones?
What is your current life goal?
What are your dreams?
What is the reason you are doing this?
You can think of some too. No matter the question, stay away from 'yes & no' questions. Those type of questions don't give a substance and aspects are the spices and flavor of your Fate game. Personally I would stick to a pool roughly twice the size of the number of aspects you want for each character. So for your generic number of aspects of 5 you would want about 10 questions in the pool. This way the characters can be diverse, but still in a way to not confuse anyone. I will probably start using this method in the future and thanks to the Red Dice Dairies for bringing it up. Please +1 and share. You can also subscribe via email to get my regular updates.