Since you're not at a table in a room dedicated to other purposes (living room, dining room), crafting in a closet seems like it would feel especially purposeful. If those other rooms are shared with a significant other or roommates, sequestering yourself in the closet also can mean decorative free reign. Once you're done, you get the added bonus of being able to shut the door on any mess you've made.
Even if your closet initially seems inadequate for your stash of fabric, paper, and other crafty supplies, don't give up. With some smart organization, especially the use of dedicated containers and an eye to vertical space, you'll be surprised how much you can fit in there.
Images: 1. Lovely Design 2. Michael Fine for Casa Sugar 3. Better Homes and Gardens 4. A Field Journal 5. Jason Loper for Apartment Therapy 6. Kim Rinehimer for Apartment Therapy 7. Average Jane Crafter 8. Apartment Therapy 9. Making This Home 10. Lemon Tree Creations
Before & After: Emily Henderson Transforms a Senior's Studio Space
Monica & Austin's Charming Bungalow
Good Food to Share 
The Big Book of Small, Cool Spaces 
Apartment Therapy Presents 
The Eight-Step Home Cure 
White Enamel Four-P...
How to Make Easy 3-Ingredient Energy Bars at Home
True Greek Recipe: Paximadi Bread Salad with Tomatoes, Feta and Capers
You've used the image in #1 so many times for different posts and I never get tired of it. Perfect sewing closet imo! And the raw space is the closest to my set-up, so it feels v v inspirational for me, as opposed to ideas that will never fit in my room. Beautiful done, owner of #1!
Litter box in #9! Someday I'd like to see a roundup of creative ways to sneak in litter boxes that take into consideration the aroma immediately post-use, regardless as far as I can tell of what type of litter used...
M'elizabeth, I had to laugh when I read your post. At one time I shared my craft room with the cat box and my solution was to have a can of Febreeze on my desk. After my boyfriend and I broke up (they were his cats) I didn't have that issue anymore.
In response to the post, there is absolutely no way I could store all of my crafting stuff in a closet, but I have to admire the efficient use of space.
I love that orange two tiered organizer in the last photo. Any ideas where it's from??
It's true, Pythia! I used the first image in a roundup last week because it's just so well done (http://www.apartmenttherapy.com/dc/artistic-organization-craft-rooms-with-style-156604). I'm glad you get inspiration from it too.
#2 shouldn't count! It's as big as a room!