This is the smartest, easiest method. You are basically painting over the bumps with dirt. It’s called top-dressing, and it’s how golf courses get those greens so smooth you can roll a marble across them.
Find yourself some sandy loam. Avoid pure sand—it’s useless—and avoid clay, which turns into concrete in the sun. You want soil that feels like a crumbly chocolate cake. Not the dry kind. The moist, delicious kind.
Mix your soil with compost in a roughly 50/50 ratio. This is your "lawn-leveling smoothie." Pour it into a wheelbarrow, then spread it over the low spots. Don’t dump a mountain on a molehill; just a thin, 1-inch layer at a time.