Quilt as you go methods
 

OK, I've made 2 quilts in the QAYG methods and wouldn't do it again. One was the Jenny join from Jenny Haskins, very bad choice IMO, the other was bringing the larger back up, make a seam then fold on top of the block forming sashing and stitching down. What am I doing wrong? Or have I not found the right method?

Check Georgia Boonsteel. She is the queen of Quilt As You Go.
There are also methods to quilt in large sections and then put the large sections in quilt as Your go technique.

Made a Fun and Done but it is heavy and only one seam holds the blocks togather. Some seams are coming apart.

I used the methods in Marti Michell's book, Machine Quilting in Sections, for several large quilts before I got a longarm. I liked the fact that her methods could be used on (almost) any quilt, and you didn't have to do it on a block-by-block basis. The construction was also very strong. The other thing I liked about the book was that it shows several different methods and explains how to choose which method to use, based on the design of the quilt you're making.

I did the cotton method, I really like how the quilt came out BUT it is very heavy and stiff. Mind you I have not washed it, but it is really nice.

Dunster - thanks for the hint, I love Marti and was looking for some QAYG methods so I will check out that book

I tried one method where the sashing was stitched down with decorative stitches and it was quite stiff afterwards. DH liked it so he got it. I'm planning to try something different next.

There are probably 12 different methods. Some people don't like any of them because of how they prefer to work, so don't beat yourself up over it. My favorite is to quilt in sections and then assemble. Using Sharon Pederson's method is also very nice. One that I haven't tried yet - you still have a whole front and back. You cut the batting into 3rds. You only have the batting in the center. Quilt that. Then attach the batting for one side to the center. Quilt that. Then do the same for the other side. This method reduces the bulk so that you can get the center done. You also don't have to do a bunch of assembly at the end. You are just attaching the batting to batting.

I tried QAYG and gave up halfway through. I didn't like the way the sashing felt lumpy. I don't think I would try it again.