When you paint, you should always be aware of the paint's consistency. If it is too thin, it will sag and run while if it is too thick, it will crack. The first step in fixing sags and runs in paint is to use a roller with a nap to smooth out the surface of the wall. Next, use a clean cloth or sponge to wipe away any excess paint that was left behind by the roller. Lastly, make sure that the roller has dried before using it again. To fix sags and runs in latex paint, use a damp cloth to remove any excess latex before continuing with your project.