The first step in stringing your rod is to attach backing to your fly-fishing reel. This allows you to take up some of the space on the reel with a material called backing and conserve on the amount of line you'll need to wind around the reel.
Look at your reel to determine how much backing you'll need. The bigger the reel, the more you'll need to attach. Shoot for having your reel filled to about a 1/4 inch below the spool's rim. If you put too much backing on, the complete fly line won't be able to be spooled onto the reel. You'll be attaching the backing using the "arbor" knot.
2
Take the tag end (the loose end of the line, the part used to tie a knot) of the backing and wrap it around the center post of the reel's spool once.
3
Take the tag end of the backing and tie an "overhand" knot to the standing end (the rest of the line) of the backing, creating a loop around the reel. (The overhand knot is tied like the first step in tying your shoe: take the tag end, wrap it once around the standing end of the backing, and then send it back through the loop and pull it tight.
4
Leave enough length on the tag end of your overhand knot to be able to tie another knot with it.
5
Take the tag end and tie another overhand knot, pulling on the standing line so that both knots meet each other and go down tightly around the spool. When finished, you'll have tied the backing into a loop around the center of the reel. Tighten knots with one steady and continuous motion. You can also moisten the knot before pulling it tight to avoid a deformed knot.
6
Clip the ends of your knots, leaving about 1/8 inch so that they won't slip. You want them trimmed close to the knot, but allow a little room for them if they move when they tighten.
7
Test the knot before fishing - if the knot slips, you can cut it off and try again without losing a part of your line.
Tips & Warnings
Insert a pen or pencil through the center of the spool of backing. This will allow you to spin the spool more quickly and efficiently when reeling the backing onto the reel.
Practice tying the knots with rope or clothesline. The larger diameter string will be easier to work with until you get the hang of tying the knots.