I was looking at Trackers NW for summer class and their instructors had the following side business/skills they teach
Learn to make your own camping yurt class:
http://trackerspdx.com/outdoor-adventure/diy-and-homesteading/build-your-own-yurt.php Buying camping yurt and yurt bits:
http://www.campingyurts.com/index.shtml Yurt stove, water heaters, etc:
http://www.campingyurts.com/yurt-stoves.shtml Water sealant and repellent for canvas:
http://www.campingyurts.com/cleaners.shtml Class on
Making German turn-shoes class, by guy who made lovely, particolored, many buttoned SCA boot under the name of C, I think:
http://trackerspdx.com/outdoor-adventure/diy-and-homesteading/make-shoes-from-scrap-leather.php His website (check out gallery)
http://laughingcrowe.com/