So, I'm still learning, but this was FUN. I took a picture of my friend holding her son and my son. The picture has a busy, at home background.
I used the lasso tool to capture the three people in the picture and move them to a better location.
Next, I tried making it look just a smidge more realistic using the magnetic lasso tool. At the suggestion of my husband, I also inverted the photo to make the light look more accurate for the people in the picture. This took a few times of lassoing (on a laptop fingerpad...so, not the most precise of tools), but it looks better than the first attempt.