1. Choose a diabetic syringe and needle of the correct size.
The size of the syringe you need is simply dependent upon the volume of the insulin injections you will be administering. Unless you're overweight, the right size of needle is a short, thin needle. This will give you less pain. However, if you're overweight you may need a longer needle.
2. Choose a location for your diabetic insulin injection.
Insulin injections can go in a variety of areas of the body that have some fat under the skin. Typical areas for giving insulin injections include the thighs, back of arms, and stomach. As often as you'll be giving yourself insulin, you may find it a bit less painful to rotate the sites of insulin injections so that you do not become overly swollen and sore in one location. One side note is that your doctor may want you to give yourself injections exclusively in the stomach area if your doctor is seeking out the steadiest rate of insulin absorption by the body.
3. Make sure everything is clean.
You need to wash your hands and make sure you choose a sanitary syringe and needle. Syringes may be successfully reused by a single person if cleaned with rubbing alcohol between uses, but things can go wrong. In most cases it is recommended that you at least change needles for each injection, if not changing both needles and syringes.
4. Extract some fresh insulin.
Before sticking yourself with the needle, you need to make sure you have unexpired insulin in your syringe. Additionally, keep an eye out for signs that the insulin may be breaking down. If for example the insulin changes color or has debris floating in it, you should get your insulin replaced immediately. In particular, the fast-acting insulins should always be clear. If you use a longer acting insulin it may be a little cloudy. If you pay attention you will learn to recognize what your insulin looks like so that you will be able to tell when it does not look quite right.