1st....Slow down. Slowing down might mean cutting a few things out of your routine that is not very meaningful for you. Maybe you could turn off the television a little earlier or spend less time in front of it. A homemade lunch in the sunshine instead of racing to the local fast food place is another great way to win back some of the nicer moments of the day.
2nd...Next, give some attention to your mealtimes and the foods you put into your body--this is my second rule of reclaiming joy. Are you cruising through the drive-through because you are too tired to go home and cook? Eating well doesn't necessarily require hours of food preparation. It can be as simple as cutting out foods with a high fat content and eating more greens salads and/or adding cut up carrots instead of chips(at least that's what I'm doing...!) You can find some good suggestions on the bookstore shelves or online.
3rd...start having fun. Set aside time for a hobby or artistic endeavor that you enjoy. I hear so many people complain that they just aren't creative, and this couldn't be more untrue. Even if you can't paint like Leonardo da Vinci or play like your favorite rock star, you can still find enjoyment in the process of making art, playing music, crafting, repairing cars or any other activity that intrigues and relaxes you.