From 00:00 UTC on the 10th March until 23:59 UTC on the 14th March, collect lightweight feathers to put towards the new Nimble and Fletcher’s skilling outfits. Lightweight feathers can be won on Treasure Hunter or earned while training Agility and Fletching.
First, click on the feathers in your inventory to teleport yourself to Drill Sergeant Hartman in Burthorpe, or speak to Alison Elmshaper in Taverley. Both will let you trade your feathers for outfit pieces or lamps. Each outfit piece will require 500 feathers and each time you obtain one you’ll get XP equivalent to a large lamp in the related skill.
Every outfit piece you wear, grants 1% bonus while training its related skill, with an additional 1% set bonus if you wear all five pieces. If you already own both of them, you can wear Silverhawk boots in place of Nimble boots, to give you the additional 1% bonus. So, you could get the full 6% set bonus by wearing the four other Nimble items with the Silverhawk boots.
If you have lightweight feathers to spare, you can also purchase the medium XP lamps for 75 feathers each.
Lightweight feathers will be removed from game on the 28th March 2016 so make sure you use them before then!
Ironman accounts can collect feathers from doing Agility and Fletching in the same way as everyone else, however they will not be able to receive the outfit pieces.