If you seem to always be striking the ground before the ball then try this simple drill to help improve your connection so you hit the ball and then the ground.
Place a golf ball opposite your right foot (for right handed golfers) and so that it is on your target line. Hold the club just off the ground so that you do not knock the ball out of the way with your backswing and then make some swings so that you strike the ground without striking the ball. Keep working on this until you can strike the floor on the left of the ball, without hitting the ball.
Now try the same drill but actually hitting a golf ball. Set up as you would for a normal shot. Place an additional ball, or head cover opposite your right foot and then swing. Strike the ball you want to hit, without striking the ball opposite your right foot.
This drill will help you to move the lowest part of your swing - where you strike the ground - to where the golf ball you are striking at is, rather than before. With practice, this will stop you hitting fat shots and get you striking much more consistent golf shots with the benefit of added length due to the club striking the ball rather than the ground first.