This is for the MMA folks who are being "good boys and girls" and are all ready doing soft-tissue work on themselves.
Typically, the areas of focus tend to be the larger muscles like the quads, hip rotators and lats. But their are a few areas that MMA guys are commonly tight and bound up in that get completely ignored.
1. The forearms - This is even more important for BJJ guys training in a gi. I am telling you from personal experience. When my massage therapist digs into my forearms, it feels like I have chucks of thick rope in them.
2. TFL - When playing the guard position, the hip constantly flexes, abducts and medially rotates. This is the action of the tensor fascia lata (TFL) so it makes sense why it is constantly tight in BJJ athletes. The IT band also has attachments to the TFL. Being that the IT band is basically non-contractile, one would probably release IT band "tightness" better by addressing the TFL. A ball that is larger in diameter than a tennis ball tends to work the best for this (a soft ball works great but it is very hard..... be careful). "Warning": If you play a lot of guard this may bring tears to your eyes :-)
3. Traps - Neck cranks, guillotines and just MMA in general can wreak havoc on your neck. How many times have you gotten up in the morning after a hard training session and you are doing the full body turn to look to your right and left because your neck can't move (in our gym we jokingly call this Jiu-jitsu neck)? All of these things add up to tightness in the traps. Use a soft-ball on the corner of a wall and apply pressure to the trap. It has to be the corner of a wall so that you can apply more pressure and your head doesn't run into the wall.
4. Posterior Shoulder - This is more of a problem for bigger MMA athletes and bigger athletes in general. They tend to be much tighter in the shoulder complex. Because of "fighting posture" (hunch back/rounded/elevated shoulders), there is going to be a lot of barnacles growing in the posterior shoulder. I prefer to use ART (active release technique) on this area. Simply place a tennis or lacrosse ball on the posterior shoulder (find a bad spot) while going through internal and external rotation.
It's amazing to me that for how rough the sport of MMA is, there are athletes out there doing "zero" soft-tissue work on themselves. Remember, if you get injured you are going to be sitting on your couch. And the less time you are on the mat, the longer it will take you to improve your skills. Take the time to invest in your body. It will thank you for it.