Now that Notes has a dropdown feature, I've started to put my workouts in Monthly subheadings. That means they are all in one document. I tend to try lots of different workouts so wanted to try this system instead of making a note for each workout. I usually list the parts of the workout and then a link to where I got the info. That way I don't have to repeat a lot of the background info and exercise explanations. Easy enough just to click the link if I need to know later. Just started this last month so I'll let you know how it goes after a few more months.
PS. I do have individual workout notes for things that I might like to try later - with tags. But I think once I do a workout, I'll just add it to the monthly dropdown and just keep the link to the original site.