Once drywall is installed, you have to cover all the joints between drywall sheets. You need to cover the seams as well as screw holes with tape and filling. That process is called taping and mudding and isn’t too tricky, but includes several steps that have to be done one after another with proper timing. 

Taping isn’t too difficult but just one little slip would leave you with only one smooth side of the tape. You need very steady hands to get it right on the first try. The compound has to cover any screw holes, and cover mesh surfaces. Then everything has to dry thoroughly. Drying could be a long process that depends on the weather, temperature inside the place and humidity. The cooler the room — the longer drying. 

When your first coat has dried you need to sand it lightly to remove any ridges or bumps and apply another layer of compound and let it dry again. Sand it again and start the finishing coat and one more drying process. When you finish sanding the surface must be perfectly smooth. Otherwise you’ll need to repeat the last step one more time. 

It’s very important not to rush with drying steps. You have to let all layers of compound dry thoroughly before applying primer. Sometimes it could take longer than you planned in the beginning of your renovation because of the weather or any other unexpected delays. Waiting will ensure your walls are properly done and will hold for you for many years.