It's irritating when someone scuffs your bumper in the car park without leaving a note. Sometimes the damage is too big to simply smooth over with touch-up paint but too small to be worth the insurance claim. The best course of action in many cases is to repair the scuff yourself. You won't spend a lot of money and, if done correctly, your bumper will look like nothing ever happened.
Obtain the colour code for your car's paint. The car dealer should be able to tell you this or it may be indicated in the car manual. Buy a can of spray paint that matches the paint on your car.
Clean the scuffed area thoroughly, using the sponge and the soapy water. Remove all dirt, oil and grease surrounding the scuff.
Sand the area gently until it feels smooth and even, using the 400-grit sandpaper. Sand in several directions but be careful not to sand down one part more than the others. Feel the area with your bare hand to make sure that it is smooth to the touch. Clean the area again with the sponge and soapy water, removing any excess residue or debris.
Frame the area you wish to paint, using the heavy paper and the masking tape. Cover the non-scuffed surrounding area completely with the paper and make sure the paper is snug against the car's body. This will allow you to paint the scuffed area and not outside of it.
Spray some primer on the area in light coats. To avoid drips, spray from a considerable distance away and use lots of light coats as opposed to a few heavy ones. Sand down any uneven areas between the coats of primer. When the primer is dry and even, repeat this process with the car paint. When the paint is dry, apply the clear-coat paint and let it dry.
Peel away the masking tape and paper.
Be patient and thorough with your cleaning and painting. Prepare to spend several hours on the work.
Use caution when handling paint and be careful not to inhale any fumes.