The girl outfits I have made have been for smaller dogs and they have Velcro. Mia is 4-5 lbs and it holds great. I have used snaps for the boy outfits, and would use snaps for dogs over 6 lbs.
I have made one outfit so far for a boy (and I used snaps - even though it is a small size - just thought it was nicer for a boy). I have some more boy material - I just haven't made them yet. Here is a pic of the one I have made and samples of the other material.
You've definately got great talent! Zeus is 10 pounds and I have a really hard time finding sweaters/Tshirts for him. It's also much harder to find male dog outfits then female. Why can't the males sport a style too??