Cut and buff process used on tailgate:
I like to use a hard block and 1000 grit to get the clear flat. There is a plastic framed squeegee, squirt bottle with soapy water, microfiber towel, oak hard block and just out of sight is a bucket with clean water with sandpaper soaking in it.
I start with the 1000 grit and oak block and begin at one end of the tailgate. The idea is to get every square inch sanded flat removing and dirt specs, hair, etc.
Here you can see some dirt specks. I try to stay away from the edges with the 1000 grit.
It doesn't take a lot of pressure on the block just consistency. Remember to clean your surface regularly and keep it lubricated with the soapy water. If you dislodge a piece of dirt and get it under your sanding block, you will be hating it in short order.
Once the clear is flat you need to move to 1500 grit on a soft block to remove the 1000 grit scratches. I intend to use guide coat on the next panel I do in order to be sure all the 1000 grit scratches are gone. You can see the first foot or so has been sanded with 1500.
Moving on to the 2000 grit. It is tough to see your progress with these finer grits. One tip is to use solvent based wax and grease remover. Squirt it on and wipe it off with a blue shop towel and you will be able to see if there are still some deep scratches that need attention.
Here's a color shot after buffing:
Reflections: