There are a lot of different ways to frame projects. My friend Ange gets them professionally framed. They look fabulous but this is unfortunately out of my price range. I have always framed my own trying various techniques.
I've found that framing designs under glass keeps them clean and looking good. The glass is the only thing you have to clean and is a LOT easier than washing and ironing, then resetting the design.
I get most of my frames from cheap shops or department stores. I just take the measurements along (in both inches and centimetres) and get the right size. If I see a frame(s) I like I usually get them - I've got so many patterns I'm sure one of them will fit.
Most of my projects are done corset style. I'm sure there's a real word for it, but I don't know it. You'll get the idea from the picture. Basically you start at the top and go to the bottom stitching about and inch apart. Then you do the same thing with the sides. It can be pretty difficult to keep the design centered and the tension tight, but it gives a good effect in the end.
I've just started using double sided tape which seems to work well with small project. I've yet to try it on large projects, but I'll let you know how I go when I do.