I use human hair and I avoid the silky kind. I go for the kinkier kind. It looks a little like relaxed hair that isn't very silky, if that makes sense. Lately I've used water wave or wet and wavy just coz the waves the ends form after a wash save me the trouble of styling on a day I haven't got time to fuss with it.
I also try to get a color closer to my own hair color. Then just making sure you smooth your own hair as you braid helps tuck it in well. I once took a picture to show that even when your hair texture is different from the hair, you can hide that difference if you make sure to hold close to the point of cross over during braiding so you tuck your hair into the braid well.
Another tip is not to blow-dry or press hair before braiding because when you wash it, reversion will show the difference in texture more than if you had just braided your hair in its natural, unstraightened state. Here's the pic I took in 2003 to show that even coarse natural hair can be blended in well with extension hair so that it's not distinguishable within the braid: