Originally Posted by ToroSonyCat
I think the biggest no-no to stay away from is costume satin. Some more high quality satins are acceptable for SOME purposes (though some people do seem to look down on all of them regardless) but overall just try to stay away unless you want to look like a shiny mess.
I have an acquaintance who LOVES to use costume satin. Because it's cheap. He glows like a toxic neon light in photos, and you can see all the bits fraying and where all the seams don't match up and every single pucker and stitch out of line.
As one of my friends recently put it, "If you use good fabrics, your costume will look better and help cover up for some of the mistakes you might make. If you use crap fabric, it will just accentuate all the mistakes."
So go for the good stuff. It might be more expensive (But not always! Sometimes it's decently priced or there's a good deal to be had!), but it will look better in the long run.
Also, I would personally go for a better fabric is a slightly wrong shade than a cheap looking fabric in the exact color. Fabrics can be dyed (usually), but the quality itself it whatever you choose to use.
Which leads me to broadcloth. It comes in a million colors that are perfect matches for costumes, and it's cheap. It's also super thin, kind of rough in texture, and it just brings down the overall look of costumes. Good for mockups, but not so much for the final costume.
I personally use a lot of stretch cotton sateen (I am in love with it, seriously), the fabrics from Joann's Rodeo and Casa Collection lines, and Kona Cotton. I also use a lot of fabrics from the home decor aisles of stores. They have some very nice vinyls and brocade fabrics there, some of which are a LOT nicer quality than similar ones in their apparel section.