Try these simple exercises with good form and the right weight for your strength.
#1 Skull Crusher (Lying tricep extension)
Lying down, hold the bar above your head at a 90 degree angle from your body with hands shoulder-width apart. Bend at the elbows allowing the bar to lower towards your forehead. Straighten your elbows and repeat. Do 10-15 repetitions of 2-3 sets.
#2 Incline chest fly
Sitting on an inclined bench, hold two dumbbells (one in each hand). Start with the dumbbells above your head and open to the side so your arms are level with your shoulders. Be sure to keep elbows slightly bent. Do 10-15 repetitions of 2-3 sets.