If you need to work on your arms then chair dips are great!
Step 1. Stand in front of a sturdy chair. Bend your knees and place the palms of your hands on the edges of the seat. Walk your legs out until your knees are slightly bent. Now raise your toes so that only your heels touch the floor. Your arms should be straight, elbows unlocked, and your butt should be near the seat of the chair, but not touching it. Keep your body weight on your arms, not your legs.
Step 2. Bend your elbows and lower your body, slowly, so that your butt drops close to the floor. Do not let your shoulders drop below your elbows.
Step 3. Straighten your arms and raise your body to the starting position.
Step 4. Work your way up to 3 sets of 12. Be sure to maintain good form.