whether you use a scotchbrite pad, or sandpaper, start by making small "circles" with it first. Then, after you've achieved an even finish, go to "straight lines". I used to prefer only longitudinal lines, but have started to see the beauty in lateral lines too (perpendicular to the blade).
Honestly, it depends on the knife for me....whether I go parallel or perpendicular.
And use your fingers directly on the knife. On a perfectly flat knife, this would be a no-no...but the curve of the khukuri lends itself to literal hand-rubbing.
Oh, and spray some WD40 on it before you start sanding/scratching. Works better than anything other lubricant, and works much faster than sanding it dry.
The real secret is pressure. Sometimes I start out at 220 and have to press really hard to get the finish even. You'll notice the blade will be "brighter" where you pushed harder. Then, just even the rest of the blade out to that level.