My tip for gravy... any time you make beef or chicken reserve the drippings. Then when you make gravy you can add the other.
So if your making a chicken based gravy add some reserved beef drippings. It gives your gravy a fuller flavor.
Some thing else, unless your going for a white gravy try using corn starch instead. I find some times that flour will change the flavor of the gravy.
My 2 cents
