Agree on the sleep. Luckily I don't struggle that much with it, unless I'm manic. When elated manic, I don't care. When mixed, it's rough.

Number one thing for me is to take my medications at the same times, approximately, and never skip. Then stress reduction is so important. Obviously stress isn't always easy to avoid. Like right now, for me. Keeping myself busy with projects that yield good things is helpful.

I'm a very big fan of CBT coping tools. I use many. A favorite is called a "Dysfunctional Thought Record". It has a lousy name, but is a good exercise. I have also benefited a lot by pre-planning for anxiety-provoking situations and early stages of episodes. I do so again according to CBT advice. It's all a matter of challenging harmful thoughts and/or practicing/planning in my mind more reasonable reactions or "safe ones". So, if/when they may happen, I'm more prepared to take the planned healthier "routes", so to speak. Self checks are also important. All of this helps with insight into my illness, which helps to nip anxiety and bipolar episodes by the bud before they go out of control.

Grounding techniques are also helpful in some situations.