Always start a workout by warming up. This elevates your temperature and gets the blood circulating and the muscle warmed up, preventing a train or other injury. You only need to do this for 5 to 10 minutes. Then, lightly stretch all the muscles then you will be using during your activity. After your activity, hold each stretch for 20-30 seconds. Do it slowly and properly, without bouncing. That stretching before and after workout can increase overall strength gains by up to 18%. Whatever your training frequency or routine, you have to focus on your form. It is better to lift light weights correctly that to lift heavy weights incorrectly. Muscles grow by slowly working your muscles through the full range of motion, which includes a positive and negative tension (raising and lowering the weight). You have to perform each exercise steadily, avoiding locked joints, exercising through the full range of motion, and remembering to breath steadily, exhaling during the effort in raising weights. There are many creative exercises you can do with free weights. Anywhere from 8 to 15 repetitions are the norm for gaining strength, shape and tone the muscle. Varying the weights, the exercises, and frequency of your training program are all helpful in promoting growth. Eventually you will hit a plateau, where the muscles adapt to the routine and refuse to grow any more. Switching you routine every once in a while prevents these annoying plateaus and allows steady development. Don't be a workaholic. Don't train feverishly thinking that more is better. You're better off easing into the process. You increase you chances of success. When you lift weights, you're actually tearing down muscle fibers. After you've completed your workout your muscle tissues begin the rebuilding process. To allow that process to unfold properly, give your body adequate downtime in between workouts. Never work the same muscle groups on consecutive days, and never train a muscle group that is still sore from a prior workout. If you want your body to change, don't do the same workout over and over again. If you repeat the same workout, your body will begin to handle it without producing an adaptive response. That's when you reach a plateau. The best way to avoid plateaus is by periodizing your training. Start slow. Get enough; at least 30 minutes a day of some kind of exercise is necessary to really feel a boost. Do intervals, it can be especially good for energy levels. Have fun. Above all, do the kind of exercise you enjoy the most.