Footwork and timing are probably the most important for backhand.
Since your reach isnt as big as with the forehand, its hard to hit a good backhand when you are out of position. You need to get behind the ball and use your legs to get proper power on your shots.
After positioning comes timing. Lots of people hit the ball way too far in front of their body. So even if you get your footwork right, if you don’t wait for the ball to get in your ‘sweetspot’ the ball will still lack power. The sweetspot should be about a forearms length in front of your belly.
Spin control comes last. The positioning and timing is important for all shots: topspin, blocking, punching and even chopping. If you do it right then spin control will automatically be better as well.