I've experienced this problem as well. You do the work quickly, then the client drags their feet in even looking at it. When they do, they send changes in dribs

I've experienced this problem as well. You do the work quickly, then the client drags their feet in even looking at it. When they do, they send changes in dribs and drabs, costing you time and money. The solution? If you suspect a client is this kind of time-waster, include a clause about "XX days to review" and have a surcharge after that.