A fun trick to play around with in Photoshop is a variant of double exposure. While taking the photo, make sure you switch to manual focus. Take one photo with the focus on the subject, and then a second photo with the subject out of the frame. Remember to not change the focus of the camera. Once in Photoshop, Auto-Align the layers of the two photos in one document. Use a light eraser (turn down the hardness) and push down the opacity to at least below 10% to avoid harsh lines. If you're an advanced user, feel free to use layer masks to preserve the quality of the originals so you can always go back, but in all honesty, if you stick with these guidelines, it's hard to mess up.