While moving a way from chicken feathers might be somewhat intimidating to some, there's no need to be constrained by prescribed patterns in using materials.Often-but not always- this issue seems to be linked to more traditional materials. "I've got a set of grouse wings but don't know any patterns that need those feathers!"
Well no, you might not. but surely you know a pattern that needs a soft feather as a hackle, some kind of feather slip as a wing case or even a pair of feather wings. Substitution is the simplest experiment in fly tying and experimenting with different materials will help expand your understanding of the different applications of feathers, hairs and other fibres no end.
Of course you can stick to established patterns, but that's only going to teach you so much and can impede you when getting the "correct" materials for a certain fly is difficult to obtain. What do you do when a pattern from the 1800s calls for a dark hackle from a swift's back or a covert feather from a tawny owl's wing? Well short of road kill or luckily finding a taxidermy piece you need to use something else. That's much easier if you have spent a bit of time playing around with different bits of bird and animal to see what does what.
Next time you're in the fly shop, grab yourself a new bird skin or a patch and have a play around at the vice.