Detailing wood siding around windows and doors, what people get wrong

If you're running wood siding around windows and doors, the part folks botch isn't the flashing, it's the bare end grain at the cuts. Cut ends drink water far faster than the face, so seal every cut at a jamb or sill right when you make it, before the board goes up. Bevel the butt joints instead of square cuts and keep your fasteners back from the ends. My trim came sealed on all faces from a specialty hardwood supplier, so the only raw ends were the field cuts and we just kept sealer on the cart. Cheap habit that saves you a callback two seasons later.