Hi, I have been around the furniture finishing business must of my life,I am only eighteen,but I have finish more furniture in all type of finishes than most people would do in ten life-times,I have been in business for the last two years making and finishing furniture and my father as been doing it all his life and he is a master cabinetmacker.Now lets get to your finishing problem,firstly about sanding,no you do not need to sand down unless the finish that is on it already is chipped,what you need to do is de-greass,as your fingers leave body oil on it everytime you have handled it,if you go over it with a fine wirewool this will take the oil and durt off,then you can re-paint it with a brush, but get yourself a stippling brush and as you apply the paint with your paint brush you will find you leave paint in the detail go over the full door or drawer front with the stippling brush this will get the paint out of the details and also the brush marks,leaving you a top class finish.Grant