It's really preference ,me I almost ALWAYS USE pre sculpted 50 mm round from a place in UK called model display products .when I was looking to acquire another detail that folks would unmistakable know that it was from me. So if you look in my gallery almost all my single models,units ,etc are all on this. I just add things to the already sculpted mud/field detail already present. Go loo you'll see.if it's 28mm it's on these. I also looove round lipped bases ,round bases in general. I am always stoke about getting a new resin(not wood) as it cuts drills etc much cleaner. Just my two cents. Jarhead did say it's a matter of preference what you feel looks best and as long as the model don't take up the whole base ,or as long as the base doesn't swallow the mini your good. Some folks use ratios me I go by feel as there are times with a certain shape like odd geometric style bases t,where the ratios go out the window.
BAM