1. Get busy living or get busy dying. From Shawshank, I love its simplicity and also to philosophize about what it means to be living how I want.
2. Don't be a dick. Essentially an extension of the Golden/Platinum Rule but it can be boiled down pretty quickly! Can't always know other's preferences but don't act with malice, be as aware of your surroundings as you can, and humility is generally good.
3. Be grateful, you're living better than any king ever did prior to the 20th Century.
(variant) Be grateful, of the 108,000,000,000+ humans to have ever lived your life by virtually any measure is in a pretty high percentile.
4. It's highly unlikely that when someone is on their death bed they will complain that they received too many hugs from you.
5. The higher a proportion of your life is spent with quality people, the better your quality of life.
(variant) Don't waste your precious life on people who do not matter.
There are some assumptions built in but they work for my life.