Do you have those moments in the gym/park where you watch someone DO something and just think, "Cool. Must be great to be that naturally fit. Back to the same old thing I always do..." Don't. If you're not brave enough to ask that person what they're doing, how and why - go find a personal trainer and describe the move. Ask how you could do a beginner version. You have to start somewhere! I recently flicked through the Men's Health Big Book of Exercises (maybe more than once) and picked out 6 moves I haven't done before. Then I sketched them on a piece of notepaper and trekked off to the gym. Here's ONE of the moves I tried.

Pistol Squat

Pistol Squat: I got through 5 on each leg, switched to an upper body exercise and then did another 5 on each leg. Challenge yourself to get a tiny bit lower every THIRD day. Strengthens and sculpts your quads and core (balancing on one leg = involuntary abs workout!)
Try it with a bench behind you if it makes you feel more secure.