Optimizing grapples - looking for boosts to grapple

So, other than the obvious answer of "enlarge person" (valid, but already being considered), I'm wondering what I can do to effectively increase a character's size specifically for Grappling purposes, as well as any other odd bonuses.

I know that there's Poised/Imposing Bearing for Bullrush, Drag, Overrun, and Trip, but if I'm reading those right, they just adjust what you can DO them to, not your bonus to them.

Obviously, I know about Enlarge Person (if there's a version of this that will take you up two or more categories, THAT would be awesome, too).

I've got Improved Grapple, Kraken Style, and I'm planning to take Greater Grapple when I qualify.

I'm planning to slap the Brawler enchantment on their armor, and I'm planning to eventually get Dan Bong (No, we're not playing PFS).

Oh, I also took the Master of Maneuvers archetype for two levels of Monk (no, I'm not taking more monk levels, though). I also plopped down the True Professional archetype for rogue, which I likely plan to take for the remaining level unless there's a compelling reason to take a splash of something else.

Right now, at level 5, I've got a +12 to my Grapples which is decent, but I'm looking for basically anything I've missed.

Yes, I'm sure there's five billion threads on this, and feel free to direct me to any good ones, but hopefully y'all understand I ain't sorting through those five billion threads to try to find a diamond in the rough.

Arm bands of the brawler are fairly cheap and give a bonus to grappling.

Giant Ancestry human racial trait gives +1 to cmb.(trades out skilled)

Bred for War human race trait (not racial trait) gives +1 to CMD as well.

I am playing a grappler currently, and thank you for reminding me that the brawling enhancement exists.

Celestial Obedience for Falayna will give you a +4 bonus to Grapple checks and your CMD.

Also, if you guys use current Errata, be prepared to hate the new Brawler enchantment... Went from a +1 bonus to a +3 bonus enhancement. There are also Belts of Skill Maneuvers. Thorny Ioun stones.

Also, not sure if you really love Kraken Style, but you should really check out the Snapping Turtle Style, it's awesome. Snapping Turtle Clutch is really where you want to be; Immediate Action grapple attempt after an opponent attacks and misses you. That sets you up for a Pin on your next actions.

Just to make sure, you realize there is no limit to the size of the creature you can grapple (regardless of your size)?

Getting the Grab ability somehow would give you a +4 to grapple.