I'm at work, so time is short. Here it is:
Customer wanted reach adjusted closer to bars on the brakes of her child's road bike. Levers are already small, considered close reach.
Space is tight in the lever body, preventing me from sleeving a nut or other cylindrical closed spacer in there. I solved that by using a spring from a derailleur cable adjuster. It had a wide enough diameter to span the cable holes but was skinny and flexible enough to squeeze into the lever body. Using a cut-off spoke through the cable mounting hole I was able to orient the spring along the axis of the cable path. The spoke was skinny enough to allow me to feed the cable along it.
Next time I might try softer springs or cutting them a little short. I think these will work, but they could be perfecter. I just don't have time to extract, adjust and reinsert them when it doesn't seem absolutely necessary.
EDIT 16:20 EDT: Stupid perfection. I couldn't stand it "good enough," so I yanked it apart, trimmed a couple of millimeters off the springs and put it back together. It is better.