I guess this video that I made a few months ago is relevant.
On a project I'm working on called Rock in the Road, the characters were all modeled with REALLY thick cloth and many of them have many (many, many, many) layers of cloth. This cloth has some pretty intense texture too. Obviously, with all of this going on, we couldn't just select the modeled cloth, apply nCloth and have a nice day. So people ask how did we sim the cloth when it was so thick. Didn't that take forever? Well, it didn't take forever. In fact, the process is pretty quick.
Wow, I said cloth 6 times in the paragraph.
We used Wrap Deformers.
Our basic workflow.
1. Build a proxy mesh based on the modeled cloth object(s). To do this simply, you could duplicate the outer faces of the cloth object, simplify the topology by deleting extra edges until you have something reasonable then delete the history of this simplified mesh. This is your proxy mesh.
2. Make the proxy mesh nCloth and sim this.
3. CACHE for the love of Pete! (I'll get into that later, this step isn't in the video.)
4. Select the hi-res cloth object, select the proxy mesh and in your Animation menuset, go to Create Deformer > Wrap. You may need to adjust the Max Distance setting of the wrap deformer, but there you go. The hi res mesh (your thick cloth) now acts exactly like the proxy mesh (the thin, one sided cloth you made in step 1).
You may need to adjust your volume for this video. I hope you enjoy this full screen and in HD: