My favorite crop to plant is legume-rich cover crops mixes! Happy to be doing this now and putting gardens and fields to bed for the winter after all the bounty that the soil has blessed us with. My son Wali helped me put together this short tutorial on how to plant fall cover crops. Maybe it will inspire you to GROW SOIL 

Growing a cover crop (aka Green Manure) is a wonderful way to build soil organic matter, protect the soil against erosion, fix nitrogen, provide habitat for beneficial insects & pollinators and so much more! We typically plant cool season cover crops after harvesting the last of the summer garden which is typically in October here in Oregon.  Alternately, they can be planted as early in late winter or early spring as possible.  

This mixture of cool season varieties is a proven mix that we use here on our farm and in gardens. The cereal grain Oats sprout quickly and provide a vertical scaffold for the peas and vetch to climb. The Bell Beans are a small seeded Fava that sprouts quickly and provides fast growth and coverage and abundant nitrogen fixation.  A cereal grain and legume mix can grow from 2 to 5 tons (!!!) of biomass per acre, that's 40-100 pounds for a 100 square foot area.

https://youtu.be/Gt0GuoSO9vg