I have used many different materials and still have some of them around. I agree with the statement about confidence in what you tie on. Without that they're nothing. As Skip said about colorfastness. I tied a few jigs with some feathers that looked great. cast them once and they looked different, after 5 they were white with a hint of color. I just buy the stuff made for the task and make sure that I'm not just buying to buy. Some stuff is worth buying in bulk to save a little and maybe sharing some along the way. Mostly, being experimental satisfies your creative side, don't fight it.