I had my mom do this once for me. It's really not worth the effort. The labor will probably make it more expensive than just buying it outright.

It depends on what size of duvet you want to cover.

Measure your duvet, and then add 2" to each dimension. So if your duvet is 86 x 90, you need to allow at least 88 x 92.

They are pretty! I do this all the time myself. If you want a twin size duvet cover, yeah, just buy two twin sheets, and its not a problem to do. I'd buy an extra twin sheet to make the pillows with if that's what u wanted.

No. You need depth for the filler, seams, foldover buttons. I would get queen and have the leftover be edging on existing pillowcases to make fancy shams. And i would have the seamstress put on button and loop corners up top to keep that darn thing in place!

oh- and if I get the king sized or queen sized flat sheets instead, would I have a little left over for pillows? Thanks!

I'm thinking of buying a couple sheets and asking a seamstress to sew them together to make a duvet. Can I get away with buying two twin sized sheets? This is what I am looking at, if it matters

http://www.garnethill.com/mini-print-percale-bedding/bedding-bath/top-rated-products/221436