1. Meditation - It has saved my life many times over. Being able to reduce stress in my daily life and handle the pain when I am actually going through a crisis is only possible with meditation. I encourage everyone to at least try meditating, being able to be calm in stressful situations is a skill everyone should have.
2. Know your body - knowing what triggers a crisis, how to tell if you are about to get a crisis, or if you are coming down with an infection or virus is crucial sometimes it is all about timing and when you are planning something like a night out or a weekend away and your body hasn't been feeling too great you have to watch out for those signs so you can do preemptive measures as opposed to damage control.
3. Ask for help - sickle-cell is usually a solitary battle but having friends and family to lean on and ask for help can do wonders. Mentally and physically the disease is exceptionally draining and despite how much we want to be autonomous we can't do everything by ourselves we need to know when to ask for help, it doesn't mean we can't do it, it just means that sometimes two heads are better than one.
I hope that helped there are loads of tips I wish I could give like drinking plenty of alkaline water, dressing warmly, eating well but those are my top 3.