Using a tiling window manger over traditional desktop environment. For instance, I use I3. I have it set up with 10 workspaces. w1 is for the browser, w2 is for notepad, w3 is for code editor, w4 is for file manager, w5 - misc stuff, w10 - terminals. I can switch between them immediately with Super+(1-0) - no clunky animations, no waste. It's more convenient to work that way on a single monitor than using 2 monitors.