Creating/Switching Windows

<C-w>S to horizontal split <C-w>v to vertical split <C-w>q to close window <C-w>w to switch windows <C-w>h/j/k/l to switch windows

map <leader> <C-W>

… makes this much more ergonomic, since I can do <SPC>w <movement> to switch windows, or <SPC>ww to switch windows, <SPC>wq to quit.