Only skip a grit if you have a reason
Each grit removes the scratches of the one before it. Jump from 80 to 220 and you leave 80-grit scratches that no amount of 220 will remove; they only show up once the stain goes on.
A safe progression is 80, 120, 180. If the surface is already dressed, start at 120. Increasing the grit by roughly 50% each step keeps the work efficient.
Stop earlier than you think
For most furniture, 180 grit is the practical finish before stain or oil. Going higher than 220 can burnish the surface and close the pores, which actually reduces how much stain the wood absorbs.
Exceptions exist: 400 grit before a film finish on a table top, and much higher grits for turned work and pens.
Two mistakes that ruin everything
The first is not removing dust between grits. A single stray grain of 80-grit left on the surface will carve deep scratches through your 180 pass.
The second is sanding across the grain. It is tempting on a curved or awkward area, but cross-grain scratches are almost impossible to remove and they show up dramatically once a finish is applied.
Edges and end grain
End grain absorbs far more finish than face grain, so a stained end grain will come out several shades darker. Sand end grain one grit higher than the faces and consider a sealer before staining.
Ease edges very slightly with a fine grit. A crisp but softened arris survives knocks far better than a sharp one.
