I find that exercise helps me the most and I try to do at least some each day. A close second, for me at least, is having a sense of humour. I also set myself a small challenge each day, though do not always achieve this. I try again until I do.
I also believe that we have to continue to fight Parkinsons all the way. Each morning I say 'you will not get the better of me today'. If only this were true.