Hi Jenny!
I believe batteries are hazardous because they leach metals into the groundwater.
Now, I did just read that not all alkaline batteries (AA in your tv remote for example) are classified as hazardous.... car batteries, silver oxide, nickel-cadmium, and others definitely are. Because of my doubt in general (and fear that even those not classified as hazardous might in fact be), we take them all to hazardous waste drop-off day. We go maybe once or twice a year.
Here's another tip, not a major revelation or anything: turn off the light! In general.
Another thing I do which some might consider nasty or taboo, is to group toilet flushings. Especially in the summer heat, it is NOT a good idea to wait too long before flushing; however, at bedtime, for example, when my husband and I go through the toothbrushing and peeing routine, we both go and then flush. Barring anything out of the ordinary, mind you. I also try to remind myself, when doing anything inconvenient, time-consuming or oddball in order to save resources, that we have it SOOOO much easier than most of the people in the world. Compare consolidating toilet-flushes with not having plumbing at all and an open sewer running between your shantytown and the neighboring one. I'll take consolidating flushes, please.
Oh! And on paper. I rarely use virgin paper. For all drafts, all in-house memos or copies to be filed, I use scrap paper. I work in a music library; people fill the recycling bin next to the copier very quickly with scrap.
Oh! And bags at the grocery store. Now this gets me in a real knot, and thank God for automated checkout, which reduces the chance that I'll have to convince a vacantly-staring minimum-wage cashier. I bring my own bags, and I let the checker-outer know immediately not to use any bags; just send it all down and I'll bag it, I say. The waste of blue plastic bags is very upsetting to me. Cashiers double-bag unless you ask them not to; if they pull a bag off the rack and then don't use it, they throw it in the trash. This is reason for a letter to Safeway or wherever because I know they're trained to double-bag. What would be really cool is if they could be trained to use their judgment for heavier bags. That doesn't seem likely.