The best thing I can say is write down what you are going to practice and do those. Dont wander off and do something else or noodle around during practice time. This way ur practice time isn't wasted. Next thing is when doing chord changes, don't focus on speed but rather accuracy. Slow down when ur changing from one chord to another and try to observe what your fingers are doing. Try to remember the space your fingers make from one chord to another.