Make sure you have those installed first. If you use A Legend's Weapons and Vestments, uninstall it first. The higher your level, the quicker your equipment progress through tiers you've out-leveled, providing an upgrade 'fast track' if you choose to use new equipment. Progress slows exponentially the more upgraded your items become, so an iron sword might eventually become stronger than an ebony sword, but the ebony sword has more potential.

The default progression rate is balanced to keep your equipment viable without overshadowing any high tier gear you might come across. Beyond that, just play the game and watch as your equipment strengthens. There is a configuration menu that allows you to disable the mod, adjust the rate of progression, and set progression caps for weapons and armor. New with version 2.1: follower's equipment can improve too! Or maybe you like the way a weapon looks, but its damage just can't keep up. Maybe your character might intentionally build up the reputation of a weapon to sell it for a profit.

It's a lot like tempering, but you do it gradually by cleaving through your enemies. This allows for a favorite early game weapon to become a signature weapon that scales with your character. In practice, the more you use the same equipment, the more potent and valuable that equipment becomes. Wear the same pair of dragon-slaying boots for good luck? You guessed it. Single-handedly slaughter the entire Stormcloak army with a butter knife? That butter knife now has the stats and value to prove it. Simply put, Signature Equipment enables your weapons and armor to scale through achievement. A hero's gear can take on a legend of its own.

Skyrim weapon level scaling