One of things we did is messed with our thermostat and adjusted our energy plan to try using heat more strategically/less often. We also switched our trash pickup to once a month to save money (although we live in uber recycling land, so that still gets picked up weekly.) We compost food scraps which the city will pickup if we didn't have a backyard bin -- which requires almost no fuss, we stir it a few times a year.
Buying Energystar and HE appliances, putting those water saver regulators on sink and shower taps, replacing bulbs with compact fluorescents or LEDs were all one time things that we did and then didn't need to think about.
Hmm, we don't buy tissues, napkins, or bags, we use cloth handkerchiefs and napkins, and use recycled bags to line our kitchen trash and collect recycling. Still have some paper towels for those kind of messes you don't want to go through the washer though.
One thing that can be a pleasurable time suck, but can be a great hobby with kids is that we grow organic vegetables. A 4x4 foot planter box or two generally can feed a family of four with most veggies you would want.
We're also a one car and several bike family, but I admit, I use the car most often, my DH is the one who bikes or jogs to and from work.
I think like Marmee says, you should give yourself permission go easy on yourself and not make your life more complicated than necessary. I also think though for myself, a lot of the habits my (very hippie) mom installed in me at a young age with regard to eating healthy foods and recycling/conserving/thrifting have lasted my whole life, so if there are some things that are easy to incorporate with young kids, that's great.
ETA: We don't have a dryer, just some hanging racks in the basement. I can see the advantage of occasional dryer use though, but even indoors in a not really heated place in a rainy climate most clothes will dry fine hanging overnight.
