Remove any loose popcorn around the area to be patched. Tape off the spot to be patched - with some plastic hanging from the tape - this will take care of any over spray of the new popcorn installation. Mix new popcorn mix making sure you bought the same texture because popcorn comes in different courses. First spray the immediate area to be fixed and allow to dry. Remove tape and plastic and spray area again so to blend into existing area. Allow to dry for atleast 24 hours and paint. Painting popcorn ceilings can be a very tricky thing. The variables consist of was the ceiling primed before the original popcorn ceiling was installed - how much water was used in the mix when it was originally installed - was paint mixed into the popcorn mix when installed and how many coats of paint have been added, if any, over the years. Most people these days just hate the popcorn ceiling look. They collect all the dust, dirt and grease in the house. Most popcorn ceilings have been scraped away with new up to date textures installed -- mostly a hawk and trowel finish. Having said that, if you are going to paint a popcorn ceiling, your best bet is to use a heavy napped paint roller that is heavily load with paint. Roll the popcorn ceiling with the "get on it and get off of it" method. Do not keep going back over the same areas like you may do with a "normal" wall or ceiling. If you continue going over the same area with the roller, the popcorn finish will end up on your roller. This is why you use a heavy loaded paint roller so you can paint the areas with 2 swipes of the roller and move on. Do not find yourself using a dry roller or you might find yourself with more areas to patch.
Some People Spend An Entire Lifetime Wondering If They Made A Difference - A Veteran Does Not Have That Problem.