my warning sign is when I'm feeling restless depressed.
Not directly in a bad mixed episode but instead of feeling unable to do anything (my normal depressed state) I'm unable to do nothing.

And my anger shifts.
Suddenly I'm not beating myself up, but I'm also annoyed at everyone. Which leads to a death cycle of anger and guilt.

In the past (when I had no support network) this ended in bad mixed episodes with psychosis. Now I take a lot of me time and do creative stuff.