I'm not that great at the game of golf. But I won a team tournament several years ago because I could do one thing very good... I could putt. I was playing in a corporate tourney where the CEO put together his dream team of a foursome. I wasn't on it. 

I was the guest speaker for their conference and as a last minute add-on I was placed on a team with another speaker, the sound engineer and a maintenance supervisor for the corporation. We quickly learned that we each had a gift in one area. Driving, chipping, fairway shots and... you guessed it, I was the putter.

We won the tournament, much to the chagrin of the CEO. I learned that day that to be really good at one strength and emphasize that (and only that) would benefit me more than trying to be good at everything.

In leadership, sales and management, you are talented or gifted at one skill. You may be very organized, or a natural motivator, or great at connecting people, or even a star at numbers. It does you no good to work on your weaknesses. If you practice something you are bad at, you will usually get worse at it.

If you practice something you are gifted at doing, you will be better at that and become indispensable to your organization. 

Charles Swindoll told a story about the animals in the forest having classes to be "well-rounded" as animals. They studied climbing, swimming, flying and running. The rabbits were superior at running, but failed miserably at flying and swimming. Eagles who practiced climbing didn't do very well. They usually liked to do it their way and flyer up to the top. The ducks were terrible at running and hurt their feet eventually. The squirrels couldn't swim or fly and preferred to climb better than most animals. Each failed in every area except the ones they were strong in giftedness.

Sales people, managers, leaders and everyone are gifted in certain areas. It is the job of the leader in charge to place each person where they are most gifted and help them practice getting better to improve the organization. 

Work on your strengths and your niche. Stop wasting time on what you are not very good at doing and perfect your strengths.  John Maxwell says, "Practice makes habit, not perfect." Make a habit of improving and honing your strengths.