I have a system that works well for me, but then I normally only want to do this with text files. If you are wanting to also do this for other file types, then it gets more complicated because the Data>Open With menu is dynamic*. I set up multiple Keyboard Maestro macros to open various text editors using the same shortcut (command-shift-o). Here is what the macro looks like.
I name the macros with a number prefix, so that I can select the macro using only the number. That lets me use the same technique that I discussed here to create new documents from templates using one shortcut.
*You could still create the macros for applications that have non-common file types, say ‘Pages’, ‘Word’ ‘Excel’, & ‘Numbers’ as long as you understand that, for example, choosing Pages when an .xls document is selected will result in the macro failing.