I'm doing two things to these Cherry browns -- lubing the business parts of the slider and its counterpart inside the housing, and replacing the springs.

Lots of people use Krytox, which is a somewhat expensive PTFE (Teflon)-based automotive lubricant. Super Lube is about 1/4 the price of Krytox. The brush is a 3/0 and is just a Michaels' store brand brush (Artist's Touch) that's about 1/8" wide. It fits quite satisfyingly inside the slider housing channels.

The new springs are 39g, which are lighter and shorter than the stock springs. I was going for lighter, and I'm just glad that shorter isn't an issue. Well, I won't really know that until it's built, but they actuate just fine in the lab. 

Only ~50 more to go!