Rolling a joint is known as "skinning up".
"Tom Savage can't skin up cuz hes a cock faced muva fuka"
"When samo is skinning up he doesn't let me in his tent"
"When i was skinning up the 5-0 tried to arrest me but i blasted a cap in each of those muva fukas asses"
When someone rolls a joint they "skin up".
"yo dan can u skin up for me"
"ye safe.. got any skins samo?"
"nah seans got some red king skins tho"