Apart from the specific technique of injecting, there are a few general rules that you should keep in mind.

1. Expiry dates

Check the expiry dates of each item including the drug.

If you make housecalls, check the drugs in your medical bag regularly to make sure that they have not passed the expiry date.

2. Drug

Make sure that the vial or ampoule contains the right drug in the right strength.

3. Sterility

During the whole preparation procedure, material should be kept sterile.
Wash your hands before starting to prepare the injection.
Disinfect the skin over the injection site.

4. No bubbles

Make sure that there are no air bubbles left in the syringe.
This is more important in intravenous injections.

5. Prudence

Once the protective cover of the needle is removed extra care is needed.
Do not touch anything with the unprotected needle.
Once the injection has been given take care not to prick yourself or somebody else.

6. Waste

Make sure that contaminated waste is disposed of safely.