To properly pack line onto a reel, you must keep firm, even pressure on the line spool. If you don't, the pressure from a fish can make the line bite deeply into the loose mono, jam and break. You can buy a commercially made line spooler, but most anglers spool line the old-fashioned way: Someone winds the reel, while another person holds the spool on the shaft of a long screwdriver and tries to apply pressure with his hands. Friction from the spinning spool creates heat, requiring the assistant to wear a glove or use a rag. Not ideal.
During a recent trip out of Port Vila in the South Pacific island nation of Vanuatu, traveling American crewman Brett Jamison showed me a system that really improved the traditional method. He purchased two cheap tennis balls and, using a bait knife, made incisions on either side of both tennis balls. He pushed them onto a large screwdriver, one ball on each side of a spool of line. Modest hand pressure against the tennis balls provided sufficient tension to firmly seat the line, even with heavy mono.
Auckland, New Zealand