A "small closet with lots of padding" sounds like crap. Don't do it! The smaller the closet, the worse the sound, and the more sensitive the mic, the more of that crappy sound that will be heard.
The down comforter thing is do-able, IF you set it up around you in a "real" room. Give your sound some room to "breathe". Try using some clothesline or mic booms to suspend the blankets in a makeshift "tent" around you. This will help isolate your vocal mic from the ambient noise around you, as well as minimzing wall reflections reaching the mic.

moonbaby wrote: A "small closet with lots of padding" sounds like crap. Don't do it! The smaller the closet, the worse the sound, and the more sensitive the mic, the more of that crappy sound that will be heard.
The down comforter thing is do-able, IF you set it up around you in a "real" room. Give your sound some room to "breathe". Try using some clothesline or mic booms to suspend the blankets in a makeshift "tent" around you. This will help isolate your vocal mic from the ambient noise around you, as well as minimzing wall reflections reaching the mic.

Experiment #1:
Hang the comforters, blankets, etc. in a corner of the room, on both sides. Point the mic in the corner. Slide in behind it, and push it away to the right distance.

Experiment #2:
Do the "tent" as above.

Experiment #3:
Like #1, but with acoustic panels in the corner.

I've actually used a real thick curtain around my mic and stand to get ride of the small reverb from my basement walls, the sound I get is pretty good. But now I have an isolation booth built in the same area, but I still use the curtain, and it sounds even better.