Uneven wood after sanding is usually caused by applying too much pressure or spending too much time in one spot, which can create low areas or visible divots. To avoid this, always sand evenly across the entire surface, using steady, consistent motions. If you're targeting a specific defect, lightly mark the area with a pencil and gradually blend it into the surrounding wood rather than focusing pressure in one spot. Using the right grit progression and keeping your sander moving at all times are also key to achieving a smooth, level finish.