Honestly, anything even remotely ‘graphical’ works. Make six dots on your sheet, put their full HP and armor above each dot. Something like that is probably the simplest way I’ve found.
Then again…Though it may sound a little bit ‘cheaty’ of me as DM, I have ‘suddenly’ switched enemies out if one of my characters is having a really easy time, and we’re lacking appropriate drama, if you see what I’m saying. It’s not always about sheer numbers for me, sometimes you need to give a particular player a heavier role to play, or give them some impetus to overcome a limit, or you know, have another character come to their rescue when all hope seems lost.
But yeah, little visual representations of the enemies is generally the easiest way. And I called my little pad a ‘scratch sheet of paper’ since I’ll be changing the numbers so much, and shifting stuff around and all of that.
A lot of DMs prefer figurines and that sort of thing for just this sort of reason, never mind the ‘immersion’. But, I’ve never done the figurine thing.
All of this DMing talk has me considering getting in on something here soon on CC perhaps. Been a pretty long while since I played.