Check the paint label for the recommended thinner
Stir the paint thoroughly before thinning
Pour a small amount of paint into a separate container
Add thinner gradually
Use water for water-based paint
Use mineral spirits or the specified solvent for oil-based paint
Mix after each small addition
Test the consistency on a scrap surface
Add more thinner if needed
Stop when the paint flows smoothly
Strain the paint if necessary
Clean tools with the appropriate solvent or water