For what it's worth, I haven't used the 'ladder' method, but I've had excellent luck with its cousin the OCW method: Dan Newberry's OCW Load Development System
I pick a known "good" powder/bullet/primer combo from research on forums like this, then:
Session one: I do OCW as described in the link -- 5 rounds each powder charge in a round-robin fashion. I use chrono information to help interpret what I see on target. I also find OnTarget software ( On Target Precision Calculator
) helpful -- usually I will dump the chrono information and the "center of the group" Y-axis measurement from point of aim into a spreadsheet and choose my 'winning' OCW charge based on the info there. It is pretty cool to graph the information -- when you let Excel interpolate curves between your data points, the sweet spots show up pretty clearly.
Session two: I shoot 5-shot groups in .005" seating depth increments, starting .020" from the lands, and ending touching the lands (assuming the load isn't right near the max). Like OCW, I shoot in a round-robin fashion. Unlike the OCW phase, here I'm looking for tightest group.
I could certainly add more steps here -- for example, doing another couple sessions where I refine the powder charge and seating depth down even further -- but so far the above sequence (takes ~50 rounds and two trips to the range) has not failed to give me consistent sub .5 MOA loads.