How do i get smooth results when sanding?

All my woodworking experience so far has been with home renovations, but I’ve just started to build furniture and I’m having trouble getting smooth results. When sanding two pieces of wood that meet at right angles, for instance, I find it necessary to avoid crossing the joint with my sanding strokes or I create cross-grain scratch marks. But I’ve seen other people sand right across joints like these and achieve perfect results. Is this because of the quality of sandpaper they’re using or the skill of the woodworker?

Neither, actually. The trick lies in the machine. A power tool called a random orbit sander can smooth wood regardless of grain direction, with little or no cross-grain scratching. Palm-style models are ideal for general workshop use. A relatively new Canadian invention called the Sander Sitter is a device that lets you put down a random orbit sander while it’s still spinning, instead of waiting for it to stop turning after switching off. The Sitter has a crepe rubber pad that automatically cleans the sandpaper as it rests on it.