The first step is a rest 145F so I shoot for 1.25-1.5 quarts per pound for this step. Then I add enough boiling water to get to 155F for the second step (for my 5.5 gal batches generally 4-8qts boiling water). And again add a little more water for 167F mash-out (or if mash tun too full I can just drain first since I batch sparge).
The 145F and the 155F steps are the only points any conversion is happening so that's the only time to try to stay in the 1.25-2.25qts/lb.
Here's a calculator for determining how much boiling water needed to raise temperature of mash:
http://www.brewersfriend.com/mash/
A little info on the mash temps:
http://realbeer.com/jjpalmer/ch14.html
Thanks for the clarification. That's the technique I was thinking but just wasn't 100% sure in case there were other ways to achieve this mash temp increase.