I graduated from the U of A and then moved to the Tempe/Scottsdale line after graduation, so I've lived in both places. The phrase tossed around the most among my friends was "Tucson: smaller and arguably more urbane than Phoenix."
I think around the universities in both areas, you'll get a good mix of people and cultural activities. The thrifting scene and access to fabric/craft outlets is about the same in both areas, in my opinion. I love SAS Fabrics by the Pound, Goodwill Supercenter and the many very large thrift stores in Tucson. I found more secondhand designer-type stuff to hack up and good shoes in the Scottsdale/Fountain Hills areas (check out Fountain Hills, it's all very high-quality stuff in their Goodwill since the majority of the homes in that area are worth $1,000,000+). Thrift stores great and small are in both areas, but the Phoenix area is bigger and has more up-to-date clothing in stock, usually. Both cities have plenty of Joann, Michael's and Ben Franklin crafts stores to keep a crafter busy and well-stocked, and attending or teaching classes at those places are a great way to learn about crafter life in AZ. There are also nice independent yarn, scrapbooking and fabric stores peppered about both areas.
Phoenix/Tempe/Scottsdale areas have a burgeoning fashion scene, most of it based around DIY-type styles (and some of it not). There are lots of fun trunk shows and other things to do if you know where to look. www.labelhorde.com
is mostly a resource for Arizona fashion/hair/makeup, though many crafters and DIYers are also part of their online community and it's a good starting place to meet some people who may have the most current information for crafters.
The growth in both of these Arizona cities/areas has been phenomenal. In my experience, Tucson has a smaller, chill, almost out of time quality to it that is very alluring to me; the Phoenix/Tempe area has its pockets of joy, but for the most part it's a Baby Los Angeles: smaller, brattier and with more to prove. Of course, no generalization holds true all the time. As another poster said above, Phoenix gets a bad rap for having "no culture." While I wouldn't say it has none whatsoever, I will say that the "Phoenix sucks" attitude probably perpetuates a lot of its own mediocrity, and you will encounter it plenty. It's a city on the rise to being a real, major, credible metropolis and it's going through growing pains -- good, smart, creative people moving to that area will do it good.
I concur with rickrackruby: don't get discouraged by AZ in the summer. It is scorchingly hot and many activities and places operate at a reduced capacity during the death-heat of the season. Don't be discouraged -- as soon as the weather cools down in early October, there will be plenty of fun festivals, craft fairs, fashion shows, artwalks and other things to do.
I just moved from Scottsdale to Miami Beach. Good luck in Arizona and enjoy the weather and those gorgeous mountains.