Silicone boxes anchor each hook in a molded slit, so flies stay put when you open the lid and when you wade. Fishpond's Tacky and Pescador lines are built on this design, and the silicone holds up across a wide temperature range. Many have a clear lid, so you can find a pattern without opening the box.
Need a box that keeps water out? See the Waterproof Fly Boxes. To browse every box and patch, head to Fly Boxes & Patches.