The L To L drill is very helpful with showing you how the ninety degree angles in your swing work.
Being able to hinge the club is a very important part of the swing. Learn how to use the hinge drill to improve your swing.
Baseball can give you a feel for where you should be at impact. Start to feel what your right arm needs to do.
Tennis and golf are very similar. Feel how lining up your right arm is key to a solid hit.