Remember to always keep your abs tight to protect your lower back too. Try to round out your back on the way down so that you are not bending at the hips so much. On the way up, straighten out your back and even push your shoulders back a little bit. You should be able to feel each and every muscle on the way up. Knees should be slightly bent.
Giant sets are combinations of exercises for the same body part all done together successively.
This variation gives you an opportunity to increase your endurance by doing it in circuit format meaning little or no rest in between sets. Of course, you'll have to lower your normal weight in order to do these. Don't throw the weights up with your body, it's all deltoids. For this one, remember to not use momentum as well. Lift slower on the upswing, and resist the gravity on the downswing.