As technical as the sport of swimming can be, it is tough to narrow down the answer to the often-asked question, "What should I concentrate on?" So I came up with a top 10 list of steps to improving your swim for a triathlon. These aren't necessarily in any order, but should go a long way in helping you achieve your goals, whether you are a beginner or trying to go pro.
Slice your hand into the water right about at your goggle line, and drive it forward. Many swimmers attempt to get as much "air time" as possible by reaching the hand out before entering into the water, but it is actually more efficient to go through the water with your hand as you rotate from one side to the other.
Keep looking straight down when swimming freestyle. It's important to keep your head down with only a small part of the back of your head out of the water. Also, as you rotate through the water, try not to move your head with the rest of your body rotation.
In freestyle, your hands should pull all the way back past your hips. The last part of the stroke before recovery (arms coming out of the water) should be an acceleration behind you, not up out of the water.
Try minimizing your kick as you train for swimming. Most people will kick extra hard to make up for lack of balance in the water. Minimizing your kick will allow you to improve your balance, as well as conserve energy.
The best way to measure your training intensity is to count your heart rate immediately after each swim. You can estimate your heart rate by counting your pulse rate for six seconds immediately after each swim. Add a zero to this count, and you will have your approximate exercise heart rate per minute.