Here's some I did last year. I've done a few more but haven't posted the pictures yet
http://www.quiltingboard.com/picture...s-t153884.html
I didn't use stablizer, but I would discard any thin worn areas. I cut the shirts into 6 pieces: sleeves, fronts, back and yolk, washed and starched them. I gave away the plackets, collars and cuffs, but you can incorporate them into your design if you wish. The gal that took mine made a really funky prairie point border out of the collar points.
I did use light colored batting and pressed all the seams toward the darker color.
I didn't have any problems mixing heavier weight oxford cloths with lighter weight dress shirts.
Remember that there are no rules, so you can use purchased yardage for sashing or incorporate it into your block to unify your design.
Have fun!