First bit of advice- buy some freezer containers that are safe in the microwave and oven. I have some small glass round casserole dishes with lids. The reason is simple; many things you want to make just really can't be cut down to one serving. But you can make a pot of chili or spagetti sauce and divide it up into serving size portions and freeze it (do lable it - I've had a few surprises on occassion)
Second, think in terms of getting several different meals out of your meat. Go ahead and roast a whole chicken. Enjoy it. Then strip the rest of the meat off the bones and get creative the rest of the week . Creamed chicken and dumplings. Chicken and noodles. (to get the broth either simmer the chicken carcass with celery and carrots, add salt to taste and carefully strain- nasty little bones fall off when you do this- or trash the carcass and use a soup base - I use Specialty Club brand-it comes in one pound jars and lasts forever. But it tastes much better than bullion cubes.) A wonderful tossed salad with chicken and pinapple or strawberries tossed in. Or a chicken salad on a crossant.
When you are cooking only for yourself, make things that are easy or quick to prepare, also make it tempting. Use your freezer- buy several crossants or bagles toss them into ziplock freeser bags and microwave them when you want one. Buy fresh veggies at the salad bar if your supermarket has one. That way you aren't stuck with a whole head of cauiflower when all you wanted was one serving. Same thing in the fruit department don't buy a quart of strawberries or whatever, buy a handful. The key is variety.

A Sample meal

Fried or grilled Pork chop
Microwaved Sweet Potato ( use the small fist sized ones- prick all over and use the potato setting.) serve with butter and salt and pepper or butter and sprinkle with cinnamon sugar.
A good sized handful of brocoli florets-mirowaved until tender - add a paper thin slice of swiss cheese torn up and placed on the florets for the last 15 seconds.
A hard roll if you like
For a sweet- a nice stem of red seedless grapes.

For me this is the ideal singles meal, It takes less than 15 minute to prepare. Requires minimal clean up and has a lot of variety. Plus you will not find bits of it growing mold in the back of your refigerator sometime next week. Of course if you get an unexpected guest you are in trouble.