Here is my favorite tip for handling dry erase markers and erasers. After struggling for years over lost  markers and paper towels that don't erase, I found this somewhere. (I didn't say it was an original idea)  Use a Sock!!!  I just got a cheap pack of white socks from Wal*Mart. I store the markers in the socks.  This has reduced the lost markers. The socks erase better than anything else I have found. Plus, the students only have less to carry with them as they move.  When the socks get dirty, I take them and wash them. No worries about missing pairs. :) I don't even worry about getting them white; they still work.  ...