Like many, I mainly use full-screen windows (achieved by having only one window tagged as active in dwm). When I need to directly compare, copy/paste, read/write between windows(*), I'll tile two side-by-side. That's about it really. Oh, a major nuisance with floating windows in dwm is that they can flow out of the screen area, so the action buttons (cancel, ok) can only be used after dragging the window up.
* Another nuisance is that browser pages sometimes intercept selection/clipboard so a normal copy/paste isn't possible.