This is mostly a cathartic exercise and may seem defensive, but I thought I'd give it a go. I've been thinking a little about this since seeing Susan Soloman speak at U. Pitt, where she [humbly] presented her [significant] carbon footprint.
Good: I grow a lot of my own fruit and vegetables. This year I grew 5 species of herb (in two big pots), four species of lettuce, rocket, tomatoes (two varieties), chillies (three varieties), cucumbers (that turned out to be courgettes - last time I trust anyone at a car boot sale!), onions, spring onions, chinese leaf, spinach, runner beans, broccoli, potatoes, parsnips (went badly this year, no idea why), french beans, carrots (two varieties), rhubarb, raspberries, blackberries, and strawberries. I do not have a massive garden, or a team of 'staff' before you ask, the plot makes up about a third of my garden and is about 8 m x 8 m (including a small greenhouse). We obsessively recycle and compost (two composters and a heap) and have a pretty effective water butt. I think I've bought 5 new items of clothing, excluding smalls/socks, in the last five years mostly from gift cards I've received. I try to work from home as much as I can, and I've given up driving into town (it's an 8 minute walk). We buy as much local produce as we can. Our house's resting pulse is about 80 W (it's thanks to British Gas's gadget I know that). Whilst we have a tumble drier it is very rarely on. I've cut down on international travel and will try to get to European conferences (i.e. EGU) by train from now on. I probably now do 2 transatlantics a year on average, 1 being Guatemala every year for a field trip.
Bad: My commute is 45 mins each way and I probably travel to work 4-5 times a week (I am seeking to cut this down). The local trains are awful and expensive but I should revisit them I'm sure. I still fly too much (1 x transatlantic flight uses as much energy as 100 km a day for a year in the car I heard David Mackay say the other day). We're not bad at turning stuff off, but could do better. The loft is relatively well insulated, but the walls probably aren't and our windows are not double glazed. Our energy bills are below average but could be further trimmed I'm sure.
So, what's the point of this? Well, I think the first step towards a more sustainable lifestyle is to look, closely, at what you currently do and think were you could make [even small] changes that would benefit the environment. Since starting to think more about climate I've started to make these changes (I've had the veggie patch a while) and they've been easy and, not wanting to sound patronising, even fun. Why not do the same?