I know rubbish bins are meant for rubbish, but after a while they can really start to smell. It is a good idea to clean them using antibacterial and antifungicidal Essential Oils. If your bin is really on the bad side, firstly start by cleaning your bins with Bicarb and Vinegar, this is a great way to easily get rid of any real grimy bits. Then wash out with detergent to which you have added a couple of drops of either Eucalyptus Essential Oil or Tea Tree Essential Oil. Both of these oils not only deodorize but will suppress the growth of moulds and mildew. They also kill other germs too! You will want to use these two essential oils to help retard the growth of germs.
Next, to keep your bins smelling fresh make up either a spritzer or use a diffuser to place near your bin. You could use any number of essential oils you feel will make your garbage area more pleasant. Most commonly used would be Lemon or other citrus essential oil; mints, like Peppermint and Spearmint; Eucalyptus or Rosemary; or even spices like Cinnamon and Clove Bud.
Remember also it is a good idea to line your bins, keep your bins out of direct sunlight, wrap all food waste, especially meats in newspaper or suitable liners and always keep the lid on the bin closed at all times to prevent flies from laying their eggs, and unfortunately if you do see maggots appearing, leave the lid off for a couple of hours and soon the birds will happily dispose of those maggots for you.