Rin and Len legwarmers

Hi. A friend and I are trying to make Rin and Len Kagamine cosplay. We are completely new to this and kinda have a feeling for how to make everything. Except the legwarmers. We have some ideas on what we could do, but I thought I should ask people who have probably done this before and know what they're doing for a few tips. Tips would be appreciated(for anything to making cosplay actually mostly the legwarmers please.) and we'll post a picture of the end result. Thanks. :)