Making your own fertilizer
Compost tea is exactly what it sounds like - the liquid from soaking compost in water. The resulting tea has all the great nutrients that were in the compost, but in an easy to apply liquid form.
The basic procedure is to place a few big handfuls of compost into a pillow case or burlap sack and suspend the bag in water for several days. Once the water is dark and smelly (your the one who said you wanted to make your own) the tea is ready to use on your plants. You can re-use the bag several times for repeat batches of tea.
As easy at it is to brew, making compost tea isn't for everyone. If you don't have access to compost or an out of the way place to store a somewhat messy and smelly tub of tea, you're probably better off buying pre-made liquid fertilizer.