I got this off a thread on this forum hope it helps. I did the same thing this weekend and follow these instructions.
"Al - I use about 4 nickel diameter drops of FI-II on a cutting pad for an area the size of 1/4 hood, half a coupe door, a whole sedan door - about as much as I like to work at once. PC on 6. Put it on the panel and turn on the PC. Rapidly distribute the material to the entire section you plan to work. Now go back and start working it - begin with firm pressure at least 10 lbs. You should hear the PC motor slow down, maybe by 25%. Maintain this pressure and move slowly (no more than an inch per second, preferably less) over the surface, overlapping the previous pass by half a pad diameter. I usually go in one direction across the entire surface, then change to 90 degrees to that - just to help me see where I've been. On Richard's car I probably did this for 10 minutes or more for the first FI-II pass. The material begins to dry out, and you start to get an accumulation of white powder. Work it some more. When it is really dry, reduce the pressure - if the PC is on your hood, back off to 1/2 of what you were using so there is a small load on the motor, make some more passes. Then more with no pressure, just the weight of the PC. Then still more while you support half the weight. By this time the material is almost gone, and as you move you often leave behind areas that look fully buffed out. You can move the PC faster on these last stages - maybe 3 inches per second. Do NOT add more FI-II - you'll just ruin all the breaking-down and polishing you did.
Stop, buff off and inspect. I find FI-II residue is "sticky" - so I use lots of detail spray to aid in wiping it off. If you still have a lot of SCRATCHES left, use 4 more dollops and repeat the entire process above. If you have any HAZE left (Haze is caused by scratches too fine to see with the naked eye) then you didn't work it hard enough. I do find that there is sometimes a slight un-evenness to the look, with sections looking SLIGHTLY hazy - don't worry, this will go away when you follow it up w/ SMR. Every car I've done has been a little different. Best case, when you're done with the FI-II it is ready to wax. But I think SMR or at least a non-abraisve polish like some of the Meguiar's products will help even out the look."