Start with those who have good relevant abilities but test them. Keep going until you are happy. Then keep watching them and change as necessary.

For Captain you want a 'performer' - your favourite player is usually the man to start with (unless your favouritism is misplaced) but you want your Captain to be the guy who is effective and makes an impact regularly. (I also like him to have good creative attribute but who knows).

There's no blue print - some players are just good at some things regardless of stars or Q but be careful because changing those players too much can break them.