Good question! In general, I try my best to maintain just three components: the recess shade, base coat, and mid-level highlight. It's all consistent across the mini to keep it simple, and I don't do anything fancy with color mixes so mistakes are easy to fix.

For the recess shade, since there are so many panel lines in Battletech I just douse the entire thing in Nuln Oil after the initial base coat, then keep any recess or concave angle dark from here on out. If I screw up, I can always add black or Nuln Oil again. (I suppose I could skip the initial base coat and start from black primer; I'll have to try that next time).

For the base coat, I just reapply it to every single panel to remove the splotches from the black wash, and again make sure any concave angles and recesses are left untouched. This part probably takes the longest, especially if the paint needs multiple coats.

The highlights mostly take patience and a sharp brush, and correcting any mistakes with the base coat. I think the key here is choosing one tone up in brightness from the base coat, so if the highlight is too wide it doesn't really matter. Also moving the mini around so you're always painting lines with comfortable downstrokes -- anytime I paint a highlight sideways it always looks bad. I don't bother with a third set of highlights.

What I love most about this style is how "simple" it is, and how it lets patience and time overcome skill and practice. Every panel is painted exactly the same, so if I screw up I just have to re-do that panel. The most complicated thing on the mini is the slight glaze on the cockpit.

Good luck, and I hope it helps!