Minus the three letter acronyms, wukkadb gave the best advice imo. Always stretch after you're done working out (whether it be lifting, cardio, grappling, etc.). That is the absolute best way to increase flexibility. Also make sure that you hold each stretch for at least 30 seconds.
"There is a body of evidence that suggests stretch receptors disengage after approximately 30 seconds of stretching." -Runners World
I also highly recommend the stretches from Eddie Bravo's book Mastering the Rubberguard.