coming from another inspiring photographer (me)
1. Don't center the shot every time, use the rule of thirds, think of a picture like this
Notice how it is divided up into 9 squares, try and avoid getting your shot directly in that middle square and that should help
2. Try not to cut out your subject in the picture, for example in one you cant see the top of the guy and in another he is covered by the flag
3. try editing or using many different angles, close-ups, mid-shots, long shots, underneath, on-top, use props (take a picture through the trees, or have someone be standing on the deck while someone goes off)
4. just try and add as much variation as possible.
hope that helps. pm me if you'd like any more advice