Bit of a basic question I'm afraid, but I've not done much decorating before. My front door is a kind of reddish brown colour. It's in decent condition but I wanted to make it a darker, maybe walnut colour. Do I use stain on its own, coloured varnish, or stain and clear varnish? Does it need stripping or sanding first? How many coats? I know this is a bunch of questions but I've done a fair amount of searching the forums and all the previous posts on simlar topics seem to assume a knowledge of these basics.