A quick note about High Performance Practice.
There is no such thing as a perfect practice, and the better you get, the harder it is to find equivalent practice partners.
What to do? One answer is to fly Federer in at great expense, the other is to know how to play a game within a game.
For example you are hitting cross-courts, your power is too much for your practice partner, so when you crank it up, they miss. This leads to the ball going dead and you getting frustrated. Instead of training power that day, you can train accuracy. Practice hitting the ball to a spot and count how many you do in 3 minutes. Then try to beat that score.
Try to hit balls that are going put, balls that are wide of the alley from your opponent anyway, this just adds to the challenge.
By finding something to focus on, you can make it a challenging and tough practice even if your super tough buddies are not there for the day.