Most amateurs try to swing faster or hit the ball harder to gain distance and end up losing a ton of accuracy only to pick up a mile per hour or two of swing speed. The key to building swing speed is to train for a faster swing off of the golf course. There are a lot of aids available to help build swing speed, but the key is to make your swing and have it moving faster.
The easiest way to train for more speed is to do a simple loading and unloading drill. Using a “heavy” swing aid you want to make 3 full swings at a 1 to 2 speed on a scale of 1-10 and 10 being the fastest. Make these “perfect” full AS SLOW AS POSSIBLE swings. Then switch to a very “light” swing aid, such as an alignment rod. Swing the “light”swing aid 3 times at a 10, as fast as you can, maintaining the same full “perfect” swing. Repeat this rotation for 3 to 4 sets. You can do this daily or a few times a week.
With this type of training you will be able to create and handle more club head speed, and you will be able to maintain your accuracy.