Try when you take a photo to include odd numbers (1,3,5,7 etc) instead of even numbers (2,4,6 etc). So taking photo of three people is better than two, and taking photo of five is better than four. Its one of the rule of composition. Odd number subject in the photo balances the photo better and always look better.
The above photo is an example, I waited until the third person came into the picture and took the photo. Dont you think it looks much better with three? let me know