No excess is left, and no sanding required. Two other elements on a building often need some attention. When it is in bad condition, we recommend replacement by other tradespeople. If the majority is sound, then we use a patching product that comes in rolls and is basically tar with aluminum foil backing. This is not a permanent repair, but usually lasts the lifetime of the paint job.
Gutters can also be a problem.
If they are correctly pitched so that water runs out and doesn't collect in low spots, we treat them similar to other trim. If they are wooden, we will clean, apply the epoxy consolidant to effectively seal the interior, and then apply a couple of coats of paint. If they are made of sheet metal, the tar foil can be used to patch. They are an integral part of the weatherproofing of any home and should be treated as such. We discover new and better procedures all the time.