Here are some tips that have worked for me in the last year.
1) Take care of yourself. Take a multivitamin, eat as best as you can, get out and walk, run or some physical activity. Even when I don't want to I at least go for a walk. Put on some music and just go. I always feel better after this and ready to take on the rest of the day.
2) Get it out. Journal, doesn't have to be formal, or grammatically correct, just get it out. This is something I do on a regular basis, good days or bad. I can then go back to it and re read it and often times debunk my negative thinking and turn it around. This is sometimes how I notice triggers for my anxiety and I can try to come up with better ways to deal with it should that happen again.
3) Friends and Family. I have a few friends that I have code words with. If I send them a text say with the word "orange" they know that I need someone to talk to, having a bad day etc. They call, no judgement, they call and let me talk to them, I tell them what is bothering me and then they help me calm down. This helps A LOT. It helps me refocus my thinking and realize that my brain is just playing that what if game. Get someone you can trust to have these conversations with. It always helps to have a friendly ear to listen to you.
4) Time for relaxation. Every night I find time for me to relax. Usually I put on white noise and I go through the muscle relaxation right before bed. This calms my entire body and I can go to sleep. I like to use the sounds of the beach and I often picture myself on the sandy beaches enjoying the calm.
These are all things that with the help of my therapist I have made routine in my life to help me keep in check. Mind you, I still have my bad days, I still have certain things that trigger my anxiety and panic, but with some of these things in place those days are fewer than before.