Start enjoying the things you already have. The problem with many of us is that we think we'll be happy when we reach a certain level in life - a level we see others operating at - your boss with her corner office, that friend of a friend who owns a mansion on the beach, etc.. unfortunately, it takes a while before you get there, and when you get there you'll likely have a new destination in mind. You'll end up spending your whole life working toward something new without ever stopping to enjoy the things you have now. So take a quiet moment every morning when you first wake to appreciate where you are and what you already have.
I have been doing something very much like this each morning. I'll step outside with my bag & coffee and I'll take a look around me. Whether it's my garden, the sleeping child (well, young woman now) inside, my increasing good health, or simply the quiet morning, I will stop for just a moment on my doorstep and remind myself of the good things I have right now.
On the same coin, there are days when it's so very hard to get out of bed and function more than on autopilot. Anyone who has dealt with any form of depression will understand what I'm talking about. These are the moments when it's very hard to keep the feelings of gratitude in the forefront of your mind. During those times (these times), I try to list the things I am enjoying... the heat pump that is keeping us cool, the food in the refrigerator, the fabulous children I've had the pleasure of raising, and the friends who reach out to me when I have been silent for a while.
I wish you all a peaceful heart.