It’s best to find a run of days without rain. Partly cloudy days are best because the paint has less of a chance of drying too quickly.
Pressure wash from bottom to top to avoid staining. Let it completely dry for a few days. TSP (trisodium phosphate) is great for removing mold and mildew. Make sure to follow safety instructions on the package.
You can use a 2-part polyester resin filler to repair damages to your wood exterior. You’ll want to sand it after it cures.
Areas like trim and around windows and doors are caulked to keep water out. Caulk does fail eventually, so this is the perfect time to check. If it has, scrape it out, clean it, let the area dry, then re-caulk it.
Sand areas you’ve repaired and that don’t have paint on it, as well as the areas around them. Then paint with 2 coats of premium quality paint for wood exteriors.