While this tip applies to all writers, it is one that's especially easy for ADHD & autistic writers to neglect because of one of our superpowers: hyper-focus.
Even when the words are flowing and even when you feel like you can't stop because you need to fix a plot hole, you still have basic human needs.
Are you hydrated? Rested? Have you eaten? Showered? Spent some time outside recently? Remember to take care of yourself even when you don't feel like you need to.