If you don’t have fancy training aids, you can simply take 25 hard, full cuts with your bat. Do this 3x a day with rest in between. This helps increase bat speed and, again, you don’t need anyone to help you do this hitting drill.
Or if you prefer to work hitting technique, do what Crystl Bustos suggests, go through your swing with your bat in super slow motion. Pay attention to your body positioning throughout your entire swing. If you get out of position, stop and start over. I like doing this hitting drill up against a wall.
Stand a bat’s distance away from the wall with your toes and belly button pointed toward the wall. Go through your swing, from start to finish, in super slow motion. Your bat should not hit the wall. Your bat head should stay very close to the wall all the way through full extension!
Don’t have a bat? Get a bath towel. Bunch up one end to hold in your right hand and the other end to hold in your left hand. Get into your batting stance.
The towel will be draped over your back shoulder probably. Take 25 hard swings with the towel as your “bat.”