Not wanting to accumulate too much "stuff," I like the sheet of paper approach, or as an alternative, a drawing/lap board that can be cleared by hand or with a ruler or piece of cardboard. Right now, I use a bowl that is big enough for a tin of tobacco, that I work over to catch the dropped leaf. An old game board that folds in the middle might do, a checker board or Candyland for that matter. I like avoiding extra purchases, not for the expense but for the clutter. Then there's the good old food tray with edges to catch the leaf. If you use something re-purposed, it might be good to make a label, "Pipe Tray" or something, so it wouldn't get sent off to Goodwill by a family member.