practicing norms for ranked, teambuilder vs draft

yup, you have to be ready for any role in ranked. You really want to practice? go into draft and say fill. Grab a champ for the last role available and practice.

ah ok , ive been doing that as my warm up matches, (usually play a few prior to ranked, not sure if thats common practice.

Dont practice in TB. Much more likely to have an early surrender and than you'll never learn late game tactics.

I'd recommend draft so that you can get experience with the pick/ban phase of the game and adjusting your picks to suit the enemy team.

Teambuilder all the way. That way you can practice specific roles with specific champions.

The problem with TB is that it allows mirror matches, and without pick/ban phase some champs are better or worse than they would be in Ranked.

If you're looking to practice a specific lane/role/champ, though, Team Builder is really nice.