I find microfiber works well for the not quite mirror finishes on some things, but if you really want a true "mirror" billet finish it's not fine enough. I use a two step process on some things. Very lightly use something like a microfiber with a relatively mild polish for the first stage. Then I need to use an even finer and softer white linen cloth with a fine billet polish for the 2nd stage. Even then, I can't get it absolutely perfect sometimes. This is a very frequent thing for me considering the amount of billet and polished aluminum on my car.