You both have mentioned really good measures! I think it's important to realize that both that while manic, mixed, and depressive episodes are all distinct and have their own challenges to keep in mind -- there are core things that help with all of them like was already mentioned-- routine, diet, avoiding alcohol/drugs, etc. One that I would add that I personally used for a while was a journal and mood tracking. By itself it won't prevent anything, but knowing is half the battle -- if you're reflecting and noticing symptoms, you can better prepare yourself. My go-to strategies now are actually DBT based skills. I've heard some negative talk about the therapy because of its origins and its design but it's components are very solid for mood regulation, which is what we deal with -- a mood disorder! There are some really good skills to help combat depression and even (hypo)mania.

Talking preventative measures, one that I think stands strong for me is knowing not just avoiding triggers, but proactively preparing for the possibility. Much like soupe said about nipping it in the bud, I like the DBT skill of "accumulating positive emotions". It's a pre-emptive strike to knowing a stressful/sad/uncomfortable moment it gonna happen. You do things you enjoy and relish in that for a while, you build up a positive feeling, to curb the anxiety/sadness/irritability of the inevitable one. I use this a lot for depression. For hypomania? Easiest tip for me is to keep my debit/credit card in my wallet and no shopping online or dating apps when i'm feeling too revved. Mixed states are hell -- just remember it will pass. Meds really are the best help there.

I know i didn't add much to what was already said, but I wanted to contribute the little I could. Good post!