Oh I'm totally insane. I've done the wick holder thing in the past (don't use candles much now, and have a cupboard full of them). I also do the loo roll thing - first on our allotments to harvest carrots as a result

. I also leave egg shells to dry on my window sill before crushing them to put on the allotment. If you dry them first, you don't get in a sticky mess, so there they are, lined up in the window for all the neighbours to wonder about.
I think the craziest thing I save (and I don't know if it works yet) is the limescale from my kettle. Every other day I rinse the kettle out, pouring the water through a tea strainer to catch the lime scale which, once dry, I put in a little tub and crush up into a powder. This is also for the allotment. If someone knows this is a futile effort, please tell me so I can stop wasting my time.
Another thing I'm sure the neighbours would benefit from being explained is my new habit of pouring the dirty water with potato peelings through a sieve into a large, black plastic cauldron (I use the cauldron because the sieve fits on the top of it perfectly). Once drained, the water is donated to the apple tree, and the peelings are left to dry a bit before being added to my compost bin.