Apologies for the N00B question

[jonwhitear]

Otherwise I assume that it is pretty self-evident - ie sand consistently until the only timbermate remaining is in the grain.

Yup. Timbermate sands easily, so you won't need to put much effort in. (I think) I use 240 grit. Make sure to use a block (ideally quite a big one) so that your surface is nice and flat. You may well find the surface is uneven, and machining marks become visible during the process. Just keep sanding till they're gone. I usually end up doing more than one application - the first one goes onto just get the surface even and flat, then the next one is much easier, just to fill the pores/grain.

I found with my ash tele that the end grain on the sides went all "muddy" with the timbermate. I ended up putting a coat of clear lacquer on first, then the timbermate, and that gave a much better result. That's just my experience though, based off on ash guitar.