I have a desk lamp which I use as a lighting source, and my background is simply my desk (Or the outdoors when I take photos there)
Focus is good, as you need to be able to make out what is happening in the photo. Blurry photos aren't appealing, even if it is by accident. I use a phone, in which you can focus by taping on the subject.
I also tend to take the same photo serval times, and use which ever one looks the best. Heck, I've scrapped some photos becuase I thought none of the photos look good.
You can also use a photo editing program like GIMP or Photoshop to enhance the photo or give it an effect if you want, weather you want to make the colors brighter or just give an effect like this:
(done by putting the subject in front of the light source and turning up the contrast and lowering the brightness)
If you choose Gimp, make sure you download it here:
There is another site going around for it that not only downloads an outdated version of the program, it's also a virus. I've even seen it in an "ad" on some search engines while looking it up. Just thought you should know.
I'm what some may call a "noob" when it comes to this as most of my knowledge on how to take photos is from two electives in my online high school that I really enjoyed.