Well, here’s what I do-can’t swear that it is any good. I rip out all the old plants. Those that look diseased (cukes and tomatoes usually)I put in the burn pile.
The healthy looking stalks and stuff either get added to the compost heap or I just dig a trench in the bed throw in the plants and cover them up.
Then I either pile on a bunch of leaves on top, or plant them with winter soil improvers like winter rye or hairy vetch. In the around late Feb or March I plant red clover to turn under for green manure a few weeks before planting.
You really know what you are doing. Sadly, I couldn’t even find winter rye when I looked for it several years ago...
I, mostly, keep a herb garden. Most of them come back the next year. But I’m getting rid of my tomatoes and eggplants and I usually just dump them. They get kinda nasty at this stage...