Glenn knows whereof he speaks. Thanks to his tip last year, I climbed Langley from one of the drainages above upper soldier lake (also did a miter basin/skyblue lake jaunt). Loved it! Actually was on a pretty easy use trail the whole way from USL to Langley. There are two drainages above (and east) of USL...the well-defined use trail navigates the the one that is almost due east of USL (by contrast, the one that is northeast looked class 3, or at least very gnarly class 2, when I scouted it from the bottom).
In terms of going to Miter Basin, that is very doable from USL. You contour around the Major General. If you don't like steep, rocky, shrubby terrain, then descending from Langley you will want to avoid the drainage on the side of the Major General to USL, and instead follow the well-defined use trail just a farther to the south down to USL. Once you get to USL, then you head toward the Major General and contour around it (a slight ascent to the top of the tree line yields a class 1 or 2 route if you look carefully). I'll try to find the trip report where I did this in reverse.
