Need advice on what to put in middle of rag quilt
I am starting to make a rag quilt out of old denim jeans and I am questioning myself of what to put in the middle. I have flannel along with the denim jeans but not sure what to use in middle. I had planned on using squares of W&N but someone told me that is too heavy. Then a friend showed me her rag quilt that she didn't put anything in the middle and said it has no warmth at all. Now I am confused?!!
Also-what size would be good to cut the jean squares? I have read that I need to take a 1/2" seam allowance and I have cut some denim already at 6 1/2" squares-is that too small?
I am looking forward to any suggestions and advice from anyone that has mastered a nice rag quilt