I said last time that I sounded lazy and that it was intentional, and that I'd talk about it later. This is later. Welcome to later.
The idea is that with a side project, motivation and managing time are the most important aspects of the project.
If you're not motivated internally (since there are no external motivations like money), you just won't do it. I ran into this twice, once after writing libraries post Twilight 1, and again in the first year or so of World. Work just slows down because it's boring. So first and foremost, you have to work on the part that is interesting, even if that means that other pieces don't get written. Yet.
Secondly, if you waste your time doing menial tasks, you never get to the interesting stuff, and the motivation detractor pulls you in again, and the project stops. Getting rid of the cruft is extremely important for a long-winded independent project. To that end I made a fateful decision to write this project in C#. This has saved me countless hours of tasks that should have fallen by the wayside in the last century. Writing a kick-ass reference counter does not qualify as interesting code. And if it does, then I'm supremely jealous. In any case, any costs of C# have been utterly overshadowed by the impractibility of not using it.
So to counter the first one, I eventually picked a specific game, rather than being working on a toolset, and I started work on specific aspects of the game. This of course shows exactly which parts of the generic system just don't work. The kicker is, I had to throw stuff away or just ignore code I'd already written! Any professional programmer can tell you that this sucks but is still common. But in an indie project where such things can sap the entire energy out of a project, it's a bit more painful.
Now, working with Bunkspeed and specifically a guy named Jamie Briant, taught me about Agile development. Maybe I'm drinking the Kool-aid here, but being agile is essential. Now, Agile development has a lot of codified and formal methods associated with it. All that is cruft. The important thing is this: Don't do what you don't have to.
So remember how I wrote this complicated proxy and server/client system for the gamedata, but never used it? It's rotted by now I'm sure. I didn't 'have' to do it, but I did, and it was a waste of time.
Aha! But there is a catch! Maintaining interest is of extreme importance! At the time, the network stuff was what I wanted to do (otherwise I wouldn't have written it, yes?). So, stopping yourself from doing what you want to is another good way to kill your project.
So which takes precedence? Being interested or being efficient? It's a good question. Ideally one that doesn't have to be answered, if you're lucky with your project. In my case, if I'd started the game instead of working on the generic solution (which I've already stated I should have), the decision would have never become relevant!
I suppose the concluding advice for this aspect is to have a goal. Know what you are aiming for and keep it in sight. If you think you're 90% there, the last 10% always becomes the most interesting. So set a goal that's 10% out, then when you get there do it again.