I took a lesson recently and the coach told me I was a step behind, but he wasn't sure why. That was a suprise for me, because I always thought my footwork was pretty good, however after some thought on it I realized that I have a tendency to stand there and admire my last shot rather than activating the feet after the shot. This was a bad habit that I had to work hard to break. Before and after the shot stay down low, and use very athletic, active footwork. Once I realized this, I discovered that I get to balls in balance much quicker, I have time to use a closed forehand stance on shorter balls, which is more powerful and more reliable for me, and I'm more able to get in quick and attack short balls for approach shots.
I found that this simple change turned me allowed me to hit a lot more winners and turned me from a counterpuncher into a more aggressive all-court player, which is what I prefer.
If you video yourself during a match you might find something similar and be able to correct it.