There are a few different methods of succession planting that can be employed in a home garden. It takes a bit of planning but will dramatically increase the yield.
The first involves fully harvesting the first plant and then planting the next plant directly in its place. Plant an early crop first followed by a heat loving summer crop. You may even be able to plant a third cold season crop for fall.
The second is done with the same crop in successive plantings. Several smaller plantings are made at timed intervals, (I work at 2 week intervals). The plants mature at staggered dates, providing continuous harvest over a longer period. Salad grees and lettuce grow best in this manner. I highly recommend this for the home gardener as it can be difficult to consume if it’s all ready at the same time.
The final is the most difficult as it requires a fair bit of plant knowledge. You will be planting two different crop simultaneously: Non-competing crops, with different maturity dates, are planted together in various patterns. You can maximize the space you are afforded with this method. Because plants mature at different dates they (ideally) will not compete for light and you can plant your rows a little tighter. A good example of this is interplanting lettuce amongst tomato rows. The lettuce matures much more quickly than tomatoes and should deliver a few nice crops before the taller plants block out their light.
Keep in mind that when planting crops in close quarters you’re increasing the opportunity for disease and laying a large toll on the soil nutrients. Be sure to fertilize regularly and nip any pest problems in the bud through active prevention.