It is so easy to feel that whatever we are doing is not enough - there are so many fantastic examples out there on the web of things people make themselves. I recently saw a tutorial for making a seriously professional-looking wallet. I fully expect to see someone posting about making their own umbrella at some point.
Of course, we can't possibly do everything - I also work a 40-45 hour week plus 6 hours of language lessons each week, I frequently arrive home at an hour starting with a 9 - just time to eat and say hi to my boyfriend before I crash. But still, when I add up the idle hours, I do get 'green guilt'.
From what I've learned so far, the trick is to make things part of your routine. Okay so I'm not on top of the bread baking yet, and I've got a list of skills I want to learn as long as your arm, but there some things (however few) which are becoming a part of my routine - I am doing them without thinking.
This must be the key - when all the little bits happen without too much effort, you can focus on the whole. When you're stressing out about the washing up or when you'll make the next batch of something, it defeats the point of trying to live simply. Stress is not sustainable, and hassle is not healthy.