When I read the title I thought that we were being invited to share our uniform making methods. Oddly I have a lot of experience with this because I've designed a lot of school clothing for Asian ball-jointed dolls. If you get a chance, you might want to google "BJD school uniforms" to see what unique designs other BJD designers have made for their dolls.
These are a few things I try to keep in mind while designing uniforms:
1. Age and body type? (A few of my dolls were child sized which made it easier to come up with unisex designs.)
2. How much do I want the male uniforms to match the female ones? (This can lead you anywhere from blazer uniforms to cardigan uniforms. If you're going for something like Serafuku for the girls then Gakuran is what typically is expected for the boys. If you're making a completely original design that isn't any of these than there maybe more flexibility).
3. Uniform changes per season? (An autumn/winter uniform would have long sleeves while a spring/summer uniform would have shorter sleeves. Uniform sweaters maybe abandoned for sweater vests or whatever suits your fancy)
4. Color scheme? (This is up to you, but bare in mind that it's more acceptable for older students to wear darker or duller natural colors, while young children are accepted in brighter more cheerful colors.)
Since you're thinking towards male characters, these are the typical parts of a male uniform:
- Some kind of dress shirt. (long sleeve and or short sleeve)
- Some kind of vest (some times sweater vest)
- A blazer or sweater or both (Although it sounds like it would be too hot)
- Some kind of pants (male children are excepted in shorts and the like)
- Some kind of accessory (like a tie, but it's optional)
- School emblem (optional)
My only comic advice is to not design an overly complicated uniform that will be hard to draw over and over and over again. I can't offer any example drawings right now because I'm about to leave for an appointment, but I hope this helps get you started down a path.