The ring-binder seems to be the most common accessory at sessions now.
I have only twice sung in public from the printed words and hated it (even when I knew the lyric I was drawn to the printed page and lost connection with the performance), although I do prepare cheat-sheets with lyrics and chords for three purposes - 1. to fix in my own mind what I am playing; 2. to act as a reminder when I revisit a song after a few years, and 3. as an aid to anyone who may be joining in with me (there are a number of people I trust to do this without rehearsal, and we NEVER have time to rehearse together). I have a rolling repertoire of about 60 songs from a total list of 200+ which I think are within a couple of hours' practice of being OK.
My method of remembering is practice, and lots of it. It's amazing how many songs my kids know all the words to simply because I've sung them to sleep - should have avoided the rude ones! I do recognise that I have a good memory and am very adaptable musically - it feels like a lot of what I do is being developed "live" as I do it, not just going through the mechanical motions - so I do not wish to criticise those who feel the need for the ring-binder crutch. Does that sound like a piece of bondage equipment?
However, I feel that in order to establish an emotional connection with the lyrics, I need to have them in memory.
If I have been asked to do something special for a particular occasion at short notice, I may use a lyric sheet with just key words, say one per verse plus one from any lines I find I forget, hidden on the floor (in BIG print!) as an aide memoire. Plus, of course, for any gig, I will have a written set list. Not that I ever stick to it....