My own recent project was turning my grandmother's rocking chair from turquoise woven wood, with a navy canvas cushion, to a glossy black with white silk seat and dark red pillow... Didn't even occur to me to take a before picture, but here are some notes for the process...
So much good information here...
About the process reader's DIY suggestions in comments
Foam cushions, cut to order
A wingback chair, start to finish, (this site is also evidence of the complete overuse of adding "chic" at the end of a phrase to create a brand)
Simpler directions, for just covering a seat
Choosing your upholstery fabric
10 months ago