Always sand with the grain. This can be a bit tricky to work out on the end grain sometimes, but if machine marks aren’t sanding out of the end grain try changing the direction of sanding 90 degrees.

Always you a sanding block.

I usually start at 80 grit and work my way up to 320, but it depends on whether you are staining or painting.

Be really patient. Don’t rush through it and you will get a better result.

JK-1s don’t have veneer tops so you won’t need to worry about sanding through the top.

Wear a dust mask.