I've got a website idea that I've been thinking about developing for around a year now, but I haven't got very far with it. A week or so ago I worked out why: I don't use the half hours. Being a full time developer, I code at work for hours at a time, day after day, so my view on coding is that one needs a long stretch to do anything serious.
But I don't get long stretches.
I get the occasional evening where I can spend two or three hours on it, but that's about once a month. If I'm going out in the evening, I tend to think that the whole evening is taken up, when actually it may not be. There may be half an hour or so between getting the children to bed and going out, and maybe another half an hour after getting in before going to bed. I realised that I think something like "well, it's only half an hour, I won't get much done, so I won't bother".
It's true that it takes a while to warm up, but still, I could use the dead time a whole lot better. If I want to get this thing written, I'll have to learn how to write code in half an hour. The first job is probably writing a list of what needs doing (which will take half an hour). Then I'll need to split the tasks into half hour chunks (a few more half hours - I'm not too hot at estimating). Then I can write a few here and there, and get stuff done.