I've always done lots of things mentioned,from using off white cone thread for piecing & quilting,making scrap quilts,use stash 1st & only buy fabric at steep sale prices.Never buy backing from a LQS.....will use whatever, from sheets to cheapest muslin(washed & dried a couple times),batting & flannel bought by the bolt,with 50% off coupon.Use flannel for backing & batting for wall hangings/sofa throws.
Seldom make bed size quilts.Out of space & that alone saves me a lot of $$.Buy all notions with coupons at Joanns.Use patterns found on line.It's not hard ....as I've been doing this for many yrs,2nd nature by now.