The 3 'most used' boards would be
Hot Shot 100/180- great for taking down old product at the rebalance stage (also good for pre-thinning tips)
*This board should never be used on natural nails as it is far too coarse. The 100 is good for the debulking during rebalance. The 180 can also be used on freshly applied product if your application is lumpy or unshapely
Koala - 240/1200 - the 240 can be used for the prep stage and is also a great refiner after application (if you application is reasonably smooth) The 1200 side is EXACTLY what you need for pushing your solar oil into the enhancement prior to bringing it to a high shine...
Girlfriend Buffer 2400/4800/12000 grit. The ideal finishing board after you have taken the scratches out with a 1200 grit board.
If you step down through these grits the girlfriend buffer will bring the nail to a higher gloss finish than you can get with a top coat and it will last better... These buffers come in a 4 pack. They are costly but last amazingly well
Grits to step through after application:
180 (only if needed to reshape, if you are using this a lot then you need to re-acess your application...)
240 (refine and shape, removes deep scratches)
1200 (rub solar oil in and then ram it in with this smooth grit)
Girlfriend (black and white makes grey, this is the colour order to remember going from roughest to smoothest)
hope that helps
