For us..
I refuse to reuse cooking oil..it always has a nasty taste..seems very wasteful though..
We use disposable nappies..we tried washables, but it's too much work and looking at figures on how much energy washing reusables costs I'm even more convinced.
We now buy the 'moltex' biodegradable ones..since we had them..no nappy rash etc, but still feel a bit guilty..
We do the bulk of our shop in the supermarket most weeks..theres only so much you can get from local butcher/farmers markets etc..
I buy lithium batteries..nothing worse than a battrey running out at a cruial moment and these last for ages..