A compost pile will work fine, especially if you use worms. See next question. Worms are great. They will crawl into your pile anyway, but you can speed things up by adding more. Charles Darwin discovered that worms help make soil, by digesting garbage and outputting, so to speak, enriched soil.
Coffee grounds are great in compost.
Starbucks Coffee stores will give you great big bag fulls for free. Stir them in, though, or they might clump together. Just add as much material as you can while you are making the compost. When your pile is at least 3 feet high, or when much of it has turned into compost. To help Mother Nature replenish the earth.