Basically after I make a good swing, I may totally lost it after a few swings. Let's say I hit 90 mph on my best swing, then I drop to 80 mph after a few minutes just because I made a few small mistakes, it could be just a slight angle change or tension change in my arms, hands, wrists, some parts of my body get a little fast or slow, or maybe my body just gets tired and the muscles go out of sync. It's like one or two small mistakes and I lose all the power. How do you guys practice to remember the best swing?