"With all that vintage clothing what does your closet look like? And what sort of moth protection do you use?"
Well, here are a few quick snaps of my closet and an extra rack of suits. Nearly everything in these photos is my own personal vintage. I keep my sale items in another area. It's a little crowded but it works.
A quick note on hangers. You'll notice I don't have any metal hangers; that's because metal hangers will eventually oxidize and rust on the clothing, thereby ruining it. Plastic hangers aren't bad though if the garment is heavy they tend to bend and often times the hanger can be too narrow. I prefer wooden hangers as they're usually fairly thick, often have a natural shoulder shape to them, they're sturdy and will absorb moisture.
As for moth control, I use a variety of techniques since I have so much.
First is mothballs. I use these sparingly since they can be harmful and they are strong smelling. A few mothballs in an enclosed area will go a long way.
Next is Cedar. I the above photos you'll notice that there are Cedar rings on the hangers. Cedar is a good smelling natural moth deterrent that isn't harmful to your suits or yourself.
Third is another natural deterrent: sunlight. Most closets are pretty dark and enclosed. Moths love the darkness. Therefore, open your closet on a sunny day and let the light in.
Fourth: keep your clothes clean. Mothes love to munch on not only the garment itself but also any left over food or crud they can find. Now, I'm not saying you should dry clean your suit after every wearing since too much dry cleaning is harmful, but occasionally look it over, brush it and remove any staining you can with a little water and some soap. Doing this will give mothes fewer opportunities to start munching.
Lastly, mothes hate movement. Whether it be air movement or the owner changing things around, mothes don't like it. They're pretty lazy critters: they like to hang out in a dark, motionless closet while chowing down on your clothing. Rearrange your closet occasionally, rotate your suits and throw out anything that cannot be repaired or you don't use anymore.
In other words, your closet is like yourself: keep it clean, smelling good and well exercised.