Althoug to be honest, most/all of it applies to any martial arts skill
http://grapplearts.com/Gracie-Mag-Jiu-jitsu-Manual.htm
http://grapplearts.com/Gracie-Mag-Jiu-jitsu-Manual.htm
4. Repeat the moves over and over
Leaders of victorious academies in Jiu-Jitsu and MMA, Andre Pederneiras (Nova Uniao) and Sylvio Behring (Winner-Behring) dont fear being repetitive when they assure that the motto is to persist and persist and then persist some more when it comes to position-training.
(surf, for instance, is practised by nine in every ten fighters)