If your goal is more attacks I assume you're already familiar with things like Vicious Stomp which let you make extra attacks after a successful trip.
As far as forcing them to get up so you can trip them again...there's nothing that can be done during your turn.
I'm assuming you already know about the ways of generating extra attacks with Trip, and that's why you're asking because you want to be able to build up a lot of extra attacks.
There just simply isn't anything to do what you want.
Even Imbicatus' suggestion doesn't work because the creature wont try to stand up until its turn, not during yours. Now, if your just trying to get it to stand up so you can trip it on the next turn to get the extra attacks the next round....theres not much except as Imbicatus suggest. Magic that allows you to control the actions of your opponent.
You do know you can't use more than 1 style at a time right?
Question, Cudgeler Style gives a free trip in a charge attack, and if trip succesfull the enemy have to save 10+lvl+STR or become stunned for 1 round... Is that save correct?
Further down the Cudgeler Style feat tree, yes the save is correct.
Cudgeler Style = You charge for nonlethal damage and damage is one size category larger (damage increase is only for first attack of charge in case you potentially have more)
Cudgeler Sweet = You charge and successfully hit, you get to make a free trip attempt with +2 competence bonus, provoke as normal so still needs Improved Trip (or whatever equivalent) to avoid AoO.
Cudgeler Takedown = You charge and successfully hit, the damage increase lasts for until beginning of your next turn or until drop weapon; and if successfully trip an opponent with the Cudgeler Sweep feat, your opponent must succeed at a Fortitude save (DC = 10 + your character level + your Strength modifier) or be stunned for 1 round.
Master of many styles let u use more than 1 style at the same time.
Greater trip AoO occurs before the enemy is prone, Vicious stomp occurs then the enemy is prone (+4 attack), when they stand up the AoO occurs before they stand up, so u get the +4 but u cant trip em. Thats good to know.
You didn't specify you were going MoMS, only that you were going Monk.
And yes, this is correct. But the enemy would need to choose to stand up, in which case you could trip them again. However, they may also choose to fight from the ground to deny you the AoO from Greater Trip and Vicious Stomp after they have experienced it once.
You'll need high and variable reach, so you can just stand out of the enemy's reach but still threaten him. If he can't attack you from prone but doesn't want to waste his turn doing nothing, he has to stand up.
Unarmed is not the way to do this though.
I played a trip fighter with a reach weapon and the pin down feat, medium targets never came close to me until my GM figured out my opponents could crawl towards me (can't use my AoO to trip and pin down dies not trigger on move actions...)
If they are crawling towards you, then they provoke. Make a sunder or disarm attempt on them to get rid of their weapon. Or if you are a polearm fighter and have shield slam, make the AoO with the shield and bull rush them back.
Stand up = Move action that provokes an AoO.
Crawl 5ft = Move action that provokes an AoO.
There are some class abilites which let someone stand up without provoking.