I've trained in Chun Kuk Do for years (still pursuing my black belt) and I want to cross train with grappling as to be balanced for real-world combat. My current goal is to get my black belt in this system (while cross training grappling on the side) and then to get my black belts in BJJ and Krav Maga. 

So anyhow, here's my question: How best should I pursue grappling training to build on my previous training as a striker. I fully realize the need for grappling/ground training, I'm not asking about the pros/cons of "grappling vs. striking". How best can I best build on the striking training I've learned to learning/becoming skilled at ground fighting? Any ideas?