If DE's are out of the question then you're in X11 window managers realm. A popular choice is a tiling window manager, which automatically tiles any window that you open, has separate workspaces and is controlled solely with keyboard shortcuts. For X11 you may try i3, since dwm is autistic, you have to manually compile it from source to use it and recompile it every time you change something, because the config is the code. You can install i3 from your package manager and it uses a config file, like any sane program should do.
Important note: without a DE, you essentially don't have things you take for granted in Windows or KDE or any other Linux DE such as a start menu, control panel, desktop icons or anything like that. You're in the hard mode now, a window manager is just that, a window manager, does the bare essentials a desktop UI should do. Perhaps if you try it for a while you'll get used to it and find it a better experience once you figure out how to adjust your workflow with the right additions.
Needless to say, if you're not going to go with a DE, your next stop is window managers, and you're in for a ride. dwm, i3, openbox, whatever you'll try, it'll be barebones and it'll be up to you to make it usable.