The way I go about it and believe the instructions are as follows.
1. Trailer unhooked. Adjust tongue jack until trailer measures equal distance from frame to ground at front and back.
2. Measure from ground to top of tongue where your ball mounts up into.
That measurment will tell you how high the top of the ball should be on your tow vehicle with nothing hooked up.
Get what ever shank drop you need to put your ball at that height
Measure from the ground to the front wheel wells of the tow vehicle unloaded = A
Attach TT without your weight distribution bars. Measure from ground to the front wheel wells of the tow vehicle - B
Now install your weight distribution bars and get to a set-up you think is good.
Measure from the ground to the front wheel wells of the tow vehicle set-up ready to tow = C
C = between A to A +0.75"
If C is greater than A + 0.75", then you need to increase leverage of the weight distribution bars until you get to ~C= A +0.5" ideally.
C should never be less than what A was
Once you get your weight distribution bars set up. Then check the height of the trailer front and rear again.
If the front of the trailer is 1" or less lower than the back, your probably good.
If the front is more than 1" lower, than you can pitch you ball up by removing 1 washer (thats if it's the same design as my Equilizer)
If you need to lower the front of the TT a little, add a washer to pitch the ball down.
Ultimately the best set-up takes a little testing to see what tows the best, but following these basic principles will get you close.
Here is the complete instructions. Scroll down to the setup procedure.
Hope this was helpful.