SWIM will very soon be going on his first dmt trip. How much should he take? Should he start low and work up or go straight for breakthrough hyperspace? SWIM was thinking 25-30 mg but maybe he should go for broke and do 50 mg? He will be using the parsley sandwich method if that helps at all. Any opinions would be greatly appreciated!

Have you read the Attitude Page and the Health & Safethy section? Please re-read them as they contain basic information such as dose. It's important you read them because taking too much can result in extremely uncomfortable experiences to passing out or in my case projectile vomiting my dinner in a 2.5m radius while passed out. That could have ended very badly.

This thread gives detailed information on doses of DMT.

Doing extensive research is part of taking drugs, especially with psychedelics. When in doubt, do more research.