Ighalsk is not the first software project that I've worked on at home, or even the first game. But it is easily the most mature and furthest along. With earlier projects, I've had a great idea, started working on it, got a few things done, and then my enthusiasm has slowly worn off and I've given up.
With all my projects, I've only had an hour or two to spend on them in a night, and some nights that dropped to zero. Often in this time I'd get started on a task, but wouldn't have time to finish it - I might find a bug, or the task might be more complex than I'd planned for. Then I'd need to wait a day or more before I could work on it again. This was frustrating, and it made me feel like I was going very slowly.
With Ighalsk, I've generally been able to get something finished each night. Part of the reason is that I'm using Test-Driven Development (TDD) almost all the time. This means that my work cycle is usually: write a new test, run it to check that it fails, write just enough code for it to pass, check the changes in. A lot of the comments that I make when I check in changes start with "Added test + implementation of ..." Similarly when I refactor, each refactoring is small and I test it before I go further, so that when I do make a mistake, I can go back and fix it easily. It helps that the full set of tests runs in less than a minute (though I still want to speed them up further over time).
TDD has meant less bugs - or more to the point, that it's quicker and easier to fix bugs - and frequent refactoring (not to mention using Python!) has meant simpler code. Both of these factors have also helped me finish tasks more quickly and feel like I'm making progress.
Motivation has been less of a problem lately; I've got to the point that I have a playable game, where it's easy to see how any new functionality can fit in and will be usable immediately.
Doubtless it's also helped that I don't have any new games that I want to play at the moment - though often ProgressQuest is running in the background while I work on Ighalsk, and I've started playing FreeCol years and years after I last played Colonization ...