Yeah, it depends on which team you are and depends on the players you currently have. I don't think the star ratings are too important though. I think the attributes are more important.
If you're just starting off i'd suggest using the star ratings a lot, though try to look at the individual attributes and work out why they have said star ratings. When scouting loads of players at once, i tend to look heavily at the star ratings to begin with, and then once I've got a large collection of players on a shortlist, i look at the attributes to sort the good from the bad. However if i'm looking for a particular type of player, and only scouting maybe 10, i look more at the attributes to find out who'll be the best for my roles and team.