So here's what I do to try to make my pictures look okay:
1) I start with my really ugly homemade (extremely inexpensive) photo light box. Here's some great instructions for you to create one of your own, which are very similar to how I made mine.
I have 2 lights set up on either side of my box, nearest the front with the lights shining in from the top. One light is an Ott light, and the other is actually a very similar one that I found at Walmart in the craft/sewing dept. Just know that you need lights that give natural light, not the yellowed tones of standard bulbs.
(Note: I don't use this set up for my layouts, as they won't fit. I only use it for smaller projects...)
Here's an unedited before picture of my card, taken on a day that is gray and dreary, making my photo really fairly dark, even with some diffused lighting...
2) Now I have to edit my picture. This is where free is good. I upload my photos to Photobucket. Then one at a time I EDIT them.
3) Once in EDIT, I first CROP, then adjust the CONTRAST and BRIGHTNESS to reach the desired lighting I didn't manage to capture in my extremely limited photography skills. (I so need a class... lol)
4) Then before I save my edited picture, I add my name and blog address in a TEXT box. Then SAVE it over the original.
5) After it is saved, I right-click on my edited picture and save a copy to my laptop to upload here on my blog.
It sounds like a lot of work, doesn't it? But it's worth it and after you do it a few times, you get used to it and it doesn't seem so bad. Except on those days that Photobucket is being extremely annoying, which does happen from time-to-time. Ugh!
So now here's the same photo after I've edited it.
I hope I've answered your questions, and maybe even for those of you who didn't want to ask. :)