paint the wall first and the woodwork later. Acrylic paint for walls is generally applied with much bigger brushes / rollers whereas gloss or eggshell for woodwork can be used with smaller brushes which are more accurate. If the wall paint is dry it is possible to use low tack masking tape to give a sharp edge 'cutting in' to the edges of dados and skirtings where they join the wall. Most professional decorators have very steady hands and do without masking tape.