I found a gardening pin on Pinterest a while back. It caught my eye because the title said that if I did this I would increase my tomato output by 5X. Of course I had to try it!
You take a 5 gallon bucket (I had one lying around) and you drill holes in the bottom and the sides near the bottom. Then plant the bucket deep enough to cover the holes on the sides. Since I am lazy, I made sure I only had to plant it 5″ deep. Put compost about 1/4 of the way up in the bucket (I also added a little plain dirt on top to control smell and flies). Then take 5 tomato plants and plant them around the outside of your bucket. Fill the bucket with water and it filters through the compost to water the plants. You only have to fill the bucket once a week.