I usually use Windows Live to tweak the contrast, light and saturation etc. It’s normally the light that makes the big difference in shots. I turn the highlights and brightness and often exposure right up. A real photographer would probably shudder at my processing, but the look I like, and hey that’s who I’m doing this for, is overly bright photos.
I also nearly always turn the temperature down. I like my photos on the err of blue and you would never have guessed but I like ‘em pretty white too. You can also do this with an app if you have an iPhone. Qhen I first got mine I went on a serious iPhone frenzy and got a lot of phone camera apps but really none have them have honestly floated my boat that much. Nowadays I just take the photo with the regular phone camera and do the foofing later.
There are a few apps for processing too but I find it fiddly and too small to try and see what’s going on on the small screen of my phone, I much prefer getting them uploaded and doing it on the big screen.
check this basic editing tutorial.