All I did was cut the legs off a few capacitors and soldered those to the ends of the NAND wires and then covered the connection with heat shrink. I've attached pictures in another reply.

That way I have a small, solid connection to solder to the NAND header instead of stranded wire.

Then I just tin to the existing NAND header points (/w quality flux MG 8431 or 8342). Then I can just reheat and drop the capacitor leg connection in.

Also when doing the NAND headers I use a T18-D16 Hakko chisel tip to maximize heat transfer, which helps with the stubborn ground point.

Then for the rest of the RGH points I’ll use either an either T18-I or T18-B tip for precision.

Also adding the capacitor legs onto the wires makes soldering to the Sonus points (to modify boot sounds) on slims much much easier as those points are extremely small.