Uhhh ... caffeine
I find my focus positively correlates to days where I drink coffee or tea (it often takes a while to kick in though, so I'd often find myself going in to flow late at night and working for a long time XD)
I don't partake very often though, so maybe my brain isn't desensitized to the effects
Yeah, 30 minutes is hard mode; try 15, or even 10
And lmao I might try that alarm idea myself; I certainly seem to always wake up before my alarm, so it'll probably work for writing/drawing/etc too XD