I agree with Pete as regards the mitt over a sponge. No matter your choice replace after a few months. I use the TBM (two bucket method) with the older of my two mitts for the lower parts of the car.

This reduces the speed of swirls/marks pick-up. Depending on the amount of paint damage it may require a detail. I have found that with the wash, clay, polish, seal and finally wax all but the worst can be hidden or at least reduced to an reasonable level. All hard work though.