(This one's for you, Sabrina!)
Sheet-mulching is one of the easiest ways to reduce weeds in your yard or to get rid of a water-hungry lawn and replace it with something more drought-tolerant. (Solarization is a more extreme method that can rid an area of many fungal diseases, as well as weeds.)
To sheet-mulch an area, trim any current plant growth to the lowest possible height, water the area (to provide for soil microbes) and then cover the area with cardboard. Be sure you don't used waxed cardboard used to ship produce. Once the cardboard is in place, cover it with tree trimmings, which can be gotten for free from most tree trimming companies. The cardboard blocks the sunlight to the weeds, preventing further growth. To add a drought-tolerant plant to the area, simply push the mulch aside, cut a hole in the cardboard, and plant as you normally would.
You can grow a surprising amount of food in your own yard. Ask me how!