Small random-orbit or pad sanders make this job go faster. (Wallis first covers these boundaries with Synkoloid patching compound so no edge is visible after sanding.) As shown, you want to make sure that there is a feathered, smooth transition from exposed wood to old paint. For areas that might get close scrutiny, you can follow up with a 100- or 120-grit rubdown to erase any scratches.
In England, little is known of the trade and its structures before the late 13th century, at which paint guilds began to form, amongst them the Painters Company and the Stainers Company. These two guilds eventually merged with the consent of the Lord Mayor of the City of London in 1502, forming the Worshipful Company of Painter-Stainers. The guild standardised the craft and acted as a protector of the trade secrets. In 1599, the guild asked Parliament for protection, which was eventually granted in a bill of 1606, which granted the trade protection from outside competition such as plasterers.[2] Westminster Home Painting
Climate is another factor to consider. Sunlight, wind, rain and salty weather can all wear out exterior paint. Oil-based paint is durable against wind, rain and temperature changes, but sunlight tends to degrade it. Alkyd paint chalks and sheds very thin layers when it begins to wear. Latex paint is the more durable option for very sun-drenched and relatively dry climate areas. Latex paint with high vinyl content should be avoided, however. Acrylic resin is by far the more durable binder for outdoor latex paint. Westminster House Painting