first off before I try and give an opinion I want to make sure we are all on the same page with the same definition of the situation otherwise my advice is going to sound like a teacher in charlie brown...
Are we talking inverted guard..ie ryan hall style? or something else...if we are speaking of inverted guard, I play around with it a lot (i'm no expert but darn its fun to frustrate the hell outa my friends by letting them break my guard start to pass I turtle and then invert)
ok my first technique from the inverted guard I use to keep people from just pinning a knee and passing around (usually for an armbar) is I shoot my legs into them into a wheelbarrel position and turn my hips to off balance them and I end up in a backward mount position (I'm pretty famous for this position...by famous I mean I get flack by our blackbelt for going there b/c "its not worth any points")
2. as they push down on a leg to "stack" me I crisscross my legs and pull an arm into the middle spin and end up in an omaplata type position (its more of a marcelo garcia perpendicular omaplata position then the traditional parralel shoulder lock) from here its usually to the marcelo garcia kneein the ribs armbar but sometimes i can get a gogoplata too.
3. shoot for a kneebar, toehold, legsweep, this is for when they stand up to pass b/c as soon as their body is close enough to pass you bam leglock (for example see ryan hall.)
4. My personal favorite is a transition that I want to believe I invented, but no someone has done it before me. I am inverted and my opponent comes to pin both legs straight down. I circle one leg inside the elbow crook like I was playing spider guard and just dive through towards that leg until I can get perpendicular to the opponent and turn towards my stomach keeping the arm and go into a belly down armbar position....i realize this explanation is difficult to grasp, but I'm still working on the move myself. What usually ends up happening is my opponent can't reach across to lock hands because when I spin underneath their weight goes forward onto their other hand (or I've had it once where they just face planted, and really the finish to the move ends up being sort of the same as if you go for a belly down armbar/omaplata armbar and your opponent rolls.
