There's probably people here who have more insights into tuning a Leshiy 2 than myself.
My strategy is largely designed to optimize the amount of time I put into the process. So I pick my jets, then adjust the regulator until I find a sweet spot.
Jets take the most amount of time to adjust. But the regulator (if you have the REPR model) is relatively quick and easy.
So I try some jets and then turn the reg up and down until I hit my desired velocity or hit the point of "diminishing returns", i.e. where increased reg pressure gives less velocity increase than previous increments. Exactly where you draw the line is a bit of a gray zone, largely depending on if you're happy with your velocities and air wastage levels (draw the line at lower speeds to minimize air wastage). Something along those lines. I don't have a fully set system as I've only done it a few times.
Basically I have two regulators for my Leshiy 2 (well, two rear ends), the "modest power" reg+jets for long-life back-yard pesting in .22, and the "high power" reg+jets for the .30 cal or heavy .22 slugs, etc.
If it feels like I'm wasting air, I'd pick bigger jets. But by and large I haven't deviated far from Edgun's recommendations -- it's been over a year since I last touched my jets so I forget which ones I have in the gun.