To be honest, I just design and hope for the best that the emoticons I'm designing turn out well and will be a hit with the vbulletin community. 9/10 they are, though I think it helps knowing what tools I'm going to use before designing starts.
The current smiley set I'm working on are proving the most difficult to date. Monkeys... who needs them?
BTW Some of the emoticons wern't designed by me.

and the rest of the series.