DIR-Atlanta
Contributor
Not to pick nits, but that should be sheet bend (probably just a typo). Your description of the usage and method is accurate (tying two ropes of unequal diameter, rabbit under the limb, etc).... Sheep bend, ...
Someone mentioned the alpine butterfly, which is an excellent knot for creating a secure (but easily removable) loop on a bight. I have also found the tautline hitch to be a particularly useful knot for lots of things. The fisherman's knot is also a good one to use in certain situations.
It's always good to know how to tie some different kinds of knots - I don't know why, but people seem to be impressed when you can do that sort of thing.