Me, I use dvtm(1) instead of tmux, and I only have my dwm config set to run st with a dvtm session inside. This way, I can manually start st without dvtm by asking for `st` from dmenu or another terminal. I suppose it's a matter of personal taste, but when I run 'st' I don't want dvtm or tmux. If I want them I'll ask for them by specifying such (but I know this goes against the OP's question), or by pressing the appropriate dwm hotkey
This feature may rub some people up the wrong way, but it's just more food for thought.