Prep work is the most important part of any paint job. The first step is to clean all the surfaces. Removing dirt, mold, and mildew will help your paint to stick and cure better. If you use a pressure washer, be careful. Too much pressure can ruin siding and woodwork.
After the surface is dry, you may notice some old paint that’s peeling and flaking—be sure to scrape and sand all of that nice and smooth. Any bare wood should be primed before painting so that the topcoat will adhere better. Plus, some primers also help to keep mold and mildew from returning.
After the primer dries, fill any gaps or cracks with caulk to keep out moisture, dirt, and the occasional critter or insect. Using a wet finger or cloth to wipe down the caulk will improve the look of your work and help hide any surface flaws.