Check for Nicks, Abrasions and Cuts
Any line can get damaged when you hit a snag, hook a particularly large and aggressive bass or even bring the fish over the side of the boat. Since the strength and reliability of the line becomes compromised immediately after it nicks or begins to erode, getting rid of the damaged sections can save you from having your gear fail in a heated moment. In order to check for such damage, run the line between your teeth in order to feel where the line has become nicked or eroded.
Re-tie Knots Often
The strain of stretching repeatedly can warp lines and loosen knots. In order to avoid this, you should undo the knots and evaluate them every couple of casts whenever the action gets heavy. This will prevent the line from taking too much strain and the knot from becoming undone when you get a particularly large strike.
Cut Knotted Sections
Every time the line becomes knotted, the effort of undoing the knot often causes as much stress to the line as the knot itself. As the line twists and loops on itself, it steadily loses tensile strength; by undoing the knot, you may cause the line to have a significantly lower ability to stretch than it would otherwise have. In order to avoid having the line snap at a later time, simply cut the line above the knot and discard the rest of the line. Even if you could salvage the knotted section of line, it would not perform as well.
Store Line Properly
Although it seems counter-intuitive, making sure you store lines (particularly monofilament lines) properly can constitute the difference between buying line once a year and buying line two or even three times per year. Even though every type of line needs to be replaced regularly, storing it properly can prolong its useful life. Try to keep line in a cool, dark place, and make sure that the line has been rinsed and cleared of debris before storing. In order to avoid warping, as well as memory loops, make sure to properly run the line out without a lure in the water before and after each fishing trip.
Replace Line Regularly
Traditional monofilament lines have a life span of about one year. Other, superior lines can last longer, particularly the more expensive braided and fluorocarbon lines, but they too must need replacing eventually eventually. As soon as you begin to reach the estimated useful life of your line, as labeled on the box it came in, make sure you consider replacing it before it becomes too weak to use anymore.