Clean whatever you're working on, then remove the anodizing. Clean it again. Look at it in several lighting conditions and angles so you can see if there are any dents, scratches, pits. Dents have to be hammered out very carefully, I use special hammers. If the scratch isn't too deep I use a fine file to remove it. Any repairs like this will require an aggressive grit but just in those areas. If the rest of it is nice, I wet sand the repaired areas until they are at the same level then decide what grit to use, usually 400 - 600. I use lot of water so am near a sink, keep a sponge on the counter and prop the end of the piece near it. The sand paper is sitting in a container with water and a drop of dish soap. I will sand aggressively at first, cleaning the accumulated grit with the sponge and then wipe it with a towel. It's important to keep it clean between sanding so the grit doesn't build up and so you can see where you're at. It will take some getting used to in order to see when it's time to go to the next finer grit. As the grit gets finer, I will start sanding in one direction being careful not to slip off.
I prefer to do most of this by hand because this stuff is so thin it can be easily bent or damaged and power tools will create heat. I final buff these pieces on a bench buffer and am careful not to overheat. I use Mothers as a final polish and have no problems with tarnish. I do not want the dull shine from an anodized process, I want the finished piece to look like jewelry. But that's just me. I've taken new and original stainless wheel opening trim and polished it to a glittering shine. It looks really good!
believe me, there's plenty of time to be spent getting the mirror finish I achieve so don't need to beat myself up if I don't need to. I've seen posts about using a buffer to take it off but now you have that stuff in your buffing wheel. 
