I am definitely putting in a zipper, and luckily, all I know how to install is an invisible zipper! I never got the hang of the little flappy thing that covers a zipper, much to my mother's dismay. clt3, I took another look at the pillow with the corner ties (from Mrs. Howard, btw). I think you are right. Rats! It was going to be so much easier to sew a tie into the corner rather than leaving the corner free! I may still just sew it into the corner. I can't get my head around having to have cording at the corners without a flange, but yet it would need a flange to sew into the seam allowance around the rest of the pillow. Way too complex for me!

I'm horrible at paint colors so I'll stay away from that one, but I found a couple options for your window seat cushions (but I'd buy swatches and double check the color first). Here's sort of a fun stripe: http://www.fabric.com/ProductDetail.aspx?ProductID=3d512c90-27e2-4729-b420-053984bb4015&CategoryID=4f25d96b-867a-46b7-929e-b51a0b46b550 A textured solid (although check the weight on it): http://www.fabric.com/ProductDetail.aspx?ProductID=a12595aa-809b-4a0c-b02f-6fdcf655cb4a&CategoryID=d9b6236e-3df0-49f9-97c1-4096858026f9 A great indoor/outdoor option (i.e. hard wearing): http://www.fabric.com/home-decor-fabric-outdoor-fabric-indoor-outdoor-texture-fabric-bryant-indoor-outdoor-marlin-linen-spa.aspx A more traditional print? http://www.fabric.com/home-decor-fabric-outdoor-fabric-indoor-outdoor-classic-traditional-fabric-bryant-indoor-outdoor-garrison-spa.aspx Another stripe: http://www.fabric.com/home-decor-fabric-outdoor-fabric-indoor-outdoor-striped-fabric-bryant-indoor-out-door-crestwood-stripe-spa.aspx http://www.fabric.com/home-decor-fabric-outdoor-fabric-indoor-outdoor-striped-fabric-waverly-sun-n-shade-brookline-mushroom.aspx I think it's the perfect place in the room to bring in a great pattern. Then you can bring in coordinating pillows that might be the same pillows you use on your couch that tie everything together. I really recommend something hard wearing because people often curl up on window seats and put their feet up there (and critters like them too). I've had great luck with microsuede and indoor/outdoor fabrics for the cushions and pillows on my kitchen banquette.

I made some pillows last year with the overlapped back to insert my pillow forms. Some of the forms were not as full as I wanted, so I cut the pillows up to an inch smaller then used a 1/2" seam. The pillows were super "plumpy" is that a word? and then I put a buttonhole and button on the back to hold the overlapped pieces together. They turned out really nice. You can always start with a narrow seam, try your insert to see if it is the look you want, then make the seam wider if it isn't "plumpy" enough. Oh, and when you make the buttonhole, put an extra piece of your fabric behind it to reinforce it, or you could sew a loop you make of the same fabric to one side and sew the button to the other. There are such fun buttons, you can even use the pillows with the button sides up too. On one of my pillows, I put two buttons across the back because it was a large pillow (22"). Pics when you are done, please.

I think most of us answered defining “best” as plenty of choices and/or creative alternative choices. I like options for my personal look. OP had already gone to stores with specific styles.