I used to be very fond of drawing excessively long tails that appeared very fluffy and wide. It reminded me of those super-long dresses women used to wear to formal outings; the kind where a very long tail would drag on the ground. To me, furry characters with overly long tails had a sort of siren-like, mythical quality about them. An old motif of mine was to have a female with a tail long enough to hold to her neck as a pillow or a child-like security blanket. I don't use such techniques anymore, but I may go back to them one day...
The bottom line is: don't be afraid to experiment. Get a big white vinyl eraser and try different things! If something doesn't work, just erase it and try again! A professional tip I once heard was to draw several possible lines on the paper, and only erase once you find the right one!
Also, I like to allow something to develop on its own. If the idea in my head goes on the paper but doesn't look right, I modify it. Over and over again until it looks the best it can be. I've spent hours working on just facial structures. Sometimes, the final result is nothing like my original concept, which only makes the character that much more lifelike!
