Balls, such as a volleyball and a slightly bigger ball, maybe a basketball or beach ball can help you with some swing mechanics.
A smaller ball can be place between your biceps of your arms and your chest while holding a golf club. From this position begin to make a backswing in slow motion. Try to get all the way to the top of your backswing and then slowly make the forward motion through impact and into the follow thru. This drill will help you feel the connection of the arms and the body moving as one unit or what is commonly referred to in golf terms as staying connected. This will encourage the big muscles and your core to control motion of the swing rather than the hands and arms controlling the swing.
A larger ball, slightly deflated, can be placed between your knees in the set up position. Then begin to take backswings again in slow motion all the way to the top of your backswing. This drill will help you keep you lower body more stable, promote less movement with the knees (particularly the left knee collapsing or moving to much toward the right knee) and limit hip turn. You will begin to feel the separation of the upper body turning against a more restricted lower body. Most golfers are too loose with their lower body which promotes sloppiness in the swing and to many moving parts. All good golfers have a very stable and solid lower body.
A couple of pillows can be used to help you with balance and weight shift. Stand on two pillows and get into your setup position. You want to feel very balanced on both of your feet. If you are too much out on your toes you will tend to fall forward and vice versa if you are too much back in your heels, you will tend to fall backwards off the pillows. From a balanced position then slowly take a backswing to the top position. Once you get to the top of your backswing, if you have properly stacked your upper body over your right leg you will feel more pressure on the pillow supporting your right foot. This will mean you have properly loaded into your right leg. Make sure you do not move too much to the right as you will begin to feel yourself rolling your right foot to the outside of the pillow. This would indicate you have swayed too much to the right versus being stacked on the right leg.