I always use all 12 players. My #12 guy usually averages 8-10 minutes. I ideally run 7 guards in the PG, SG and SF positions.. SF type players in the PF position, and usually have pretty typical centers. For my guards I put the highest value on speed, defense and stamina. My forwards I put a high value on Athleticism, defense and stamina. And my centers a high value on athleticism, rebounding, defense and stamina. FT shooting is also something I always look at because we shoot a TON of FTs.
Have a look at my Grand Canyon team. This years team will be pretty close to being exactly what I want my team to look like. My team is usually high in team athleticism, speed, defense and stamina. Everything else is a bonus where you can get it. We're usually among the top in D2 ppg and turnovers against.