Exercise has a glucose lowering effect so don't take your shot right before exercising. Doing so would cause the muscles to metabolize the insulin faster.
Did you know that insulin is absorbed more quickly if you exercise the muscle near your shot site right after giving the shot? Recommendation: take a hot bath or rub the site.
Always use a fresh needle for each injection!!
If you use an insulin pen, hold the pen in place for 5 to 10 seconds after you inject to make sure you get the whole dose.