Which grit sandpaper should I use?

The choice of sandpaper grit depends on the task at hand. For sanding rough surfaces, use coarse sandpaper (grit 40-60), while for smooth finishes, finer sandpaper (grit 220-400) is needed. If you're aiming for a middle step, you can use medium grit sandpaper (grit 80-120). Make sure to choose the right grit for the best result!