Don't neglect your legs. I see a lot of peeps training only their upper body and over time that routine will cause an muscular imbalance. TRAIN LEGS! Need some help, come on by!
BALANCE! Perhaps the most overlooked skill as we age. However, just a little attention will serve you well later in life. It's as simple as standing on one leg while brushing your teeth and can transition to performing various exercises on an unstable surface. How is your balance?