My twenties were grim with bipolar, I still lose the plot but for me life started to get better and so here's my one long complex-simple tip, it's not for everyone and it's not easy and it might make no sense to lots of folk:
Create yourself from the raw materials you have lying around, one of them is you, and lots of them is memories, tell yourself a story based loosely on your life, but make it so that the main character (you) is made to sound fucking ace, or your dead dad is a superhero or your abuser is a monster that you slay and humiliate, whatever you need.
Don't buy into the simplified narrative of mental health - you do not have to be either i) a wailing world of desperate nonsense or ii) a fucking yoga matt. You do not need to fit the norm. 'Authentic Okay You' will not fit a template and it might not make sense to people. It's cool. It's your journey, screw facebook, screw people, just crack on with creating a version of yourself that is healthy-enough, is okay-enough, is capable-enough.
Don't aim for happy. We're not meant to be happy all the time, life is tough, life is problem-solving and challenges and putting up with stuff, we're all grasping at fleeting moments of happiness. It's ok.
Use felt tips to create yourself. I remember at Conor Aylward's house in about 2003 before I was capable of getting through the day, colouring in a big piece of paper with adjectives on of what I wanted to be: interesting, lovable, sociable, etc. It's like visualization for people who prefer words. Wrap that around your creation. You can aspire for the future while accepting what you are now, accepting what you are now is hard though, find a nugget, one thing you like, if not about yourself then about the world. Mine was rain. After a while, I got pleased that there was a sunset every day and it's free. Then I was made-up that I got to go round the Arndale for free and it was like a museum but more colourful. Whatever. Find a thing.
Try to find a place to exist that isn't your flat. Outside is good but can be dangerous so the library or somewhere. For me, it was the hospital, which I hated but grew to make mine in my head for need of a place to belong. It's still the hospital. A bit stage. A bit Facebook actually.
Romanticize the repetitive clunk. The walk to the shops, the bus, your banal workmates. Use those felt tip adjectives to change situations - if you act sociable give yourself 5 points etc. Remember it's you making decisions, some stuff is under your control, try to keep the felt tip adjectives in mind when you make decisions. Try to do stuff to get outside your head, help people, mine was facilitating workshops. It's something that changes your brain.
One of the things to aim for is being accepting enough of yourself that you can relax and change. I'm not a natural at accepting myself, I either slip into inferiority complex or superiority complex (which is when mania seeps in) so I had to achieve some bits so I could feel ok about myself. I absolutely do not mean fucking awards. I mean I needed to get so that I was feeding myself (to some degree) and keeping out of trouble (enough) and functioning as a regular irregular human. People are different.
Find your people. This is hard. It might be your person, but that's scary because then the stakes are high if something happens to them. A community is good. A hobby, a job, a sport, something, obviously for me it was poetry and a particular brand of cynical boy that i appear to have surrounded myself with.
Try to romanticise the fuck out yourself.
If all else fails, eat a banana.