Jeanne, I had to laugh at your students fighting over the "good stuff"!
I too have had to amend my soil considerably since it's pretty much straight clay here under a thin layer of topsoil, and I'm very lucky, as we have farms, and so I have spent a lot of time over the years bringing in good dirt by the bucketful. I can get nine 5-gallon buckets in the back of our SUV per trip, and have made many trips like this since I began gardening. I do have to deal with weeds that sprout in this soil, but I recognize them as such when they are very tiny, and they're easy to get rid of then. DH knows where the best soil is, and that's where I get it. We're lucky to have some deposits of the very best soil apparently, as well as not-so-great soil, of course, but naturally, I take the really good stuff.
Clay is actually very handy to have as a component, as it does hold water so nicely, and when things are really drying out, if the roots are down to clay, or it's incorporated into the upper layer nicely, your plants won't dry out nearly as quickly. We grow dryland corn and beans, and last summer we went over 2 months without rain, and the differences in types of soil in different fields was very noticeable as a component in how the crops did.
I have also worked bales of sphagnum peat into my beds over the years, and some sand as well. I don't do this much anymore, as it seems to be pretty good by now. I used to plant things with a combination of dirt, sphagnum and sand to fill the hole, which worked well for me, and helps to keep the incorporation of good materials going. I don't have a compost pile, as such, but I rake all our leaves to a narrow strip between a hedge and a fence, and let them just do their thing. When I dig there, it's amazingly lovely, and even better, I haven't had to bag the leaves and haul them out!
I feel very sorry for people who buy a new home around here and try to grow things, as many developers sell off the topsoil and leave the poor homebuyers with nothing but clay! There was an uninformed councilperson here a few years ago who was complaining that she couldn't grow anything at all, because she was in a new development, and it had been a field previously, and the farmer had just "ruined the ground" by growing crops.
Needless to say, the farmer probably improved the soil while he was using it, and certainly wasn't the one who had the topsoil trucked away! Many people thought she had really figured out what the problem was, though.