I cleared out one small bed today and found that, sure enough, the hostas were in fact coming back beneath all the weeds. This little corner bed actually gets more sun than hostas need, so I decided to move them to a shadier location that I need to fill up. These are smaller hostas and frankly, they didn't really have to be divided. But there were enough eyes that it was possible to divide each clump into two.
Division is usually pretty simple; the hardest part, I think, is getting past the fear that the plants can't handle being gently torn apart. They really can. For the hostas, I just dug up the clump, then used the jet spray on the hose to wash off most of the soil. With the roots bare you can assess how you want to divide the plant. By dividing into clumps of at least three shoots, the plants will still be big enough to look good. Once you decide where you want the division to be, it's just a matter of untangling, pulling, coaxing, and if necessary, cutting the roots to separate the plants. I immediately replanted them in a shady bed and watered well. They'll need to be kept well-watered for at least the next week.