Use the good soap. (Don't wait for things to be "perfect" or for special occasions in order to use your good things. You are the special occasion.)
If a book doesn't grab you, put it down. (There are too many things in this life that can easily distract us. Choose only the things that resonate with you.)
Write a thank-you note immediately after coming home from dinner, event or receiving a gift. (Doesn't everyone like to be thanked ? Certainly someone who invited you and spent time and/or money on you would like some small nod of acknowledgement.)
Acknowledge death and/or bad news immediately by sending a note of condolence, or speaking directly to the person the next time you see him/her. (If not, the lack of acknowledgement will be a silent barrier between you.)
If you have time to do something, do it when you are thinking about it. If not, the time will pass and you will not have it again.
Lay out your clothes the night before. (It is amazing how much time is saved in the morning when this is done. Plus it is one easy decision already made for the day.)
Plan out a week's worth of menus. (Just like getting your clothes out the night before, this is one simple step to organizing a less stressed week.)
Wear something nice when you have to do something you don't want to. (Part of the old, "act as if" adage. Sometimes dressing the part when our hearts aren't in it gets us motivated.)
Wear sunglasses and sunscreen. (Sunburn is not very attractive, nor is it healthy. Plus it can be quite painful)
Drink more water. (A simple act which has loads of health benefits: decreased headaches, less colds, more energy, improved memory, glowing skin, healthy GI tract, better mood.)
Leave the party when you are having a good time. (You will be remembered fondly as well as you will remember the event fondly.)

What about you? What has been some of the best advice you have ever received or given?