The title is perhaps slightly misleading. I think overall that coding should be fun. Figuring out how to do something and getting it to work is a mental exercise that can be pretty enjoyable, especially when you finally have something finished that you can get other people to play with. However, when launching into learning a new language, platform, framework, or basically anything outside of your regular development comfort zone, you can lose your focus on doing things the right way. This is where some discipline comes in.
[caption id="" align="aligncenter" width="400" caption="I don't know why, but the first image that came to my mind when I thought 'discipline' was Mr. T. So here he is."][/caption]
By now, we should all be doing certain things whenever we code. Writing unit tests first is important, as is writing good tests that actually prove the working of things. Using version control is a given; even the stuff you mess around with should use version control since it's hardly any work at all to add it. Building off of interfaces so that you can easily exchange implementations without messing with the code that uses those interfaces (this also goes well with testing). Decoupling your view from your controller from your business logic. These are all great things, but sometimes in the excitement of learning something new we forget about them.
Recently I began learning about Android programming. I started with their tutorials, and used them and the API reference doc to try to create my own simple program. The idea was to create a simple game, something that shouldn't take too long but that other people could play and have some form of enjoyment from. I decided to create Zilch (also known as Farkle). Since the portion of android that is newest to me is building and manipulating the view, I ended up writing code that was very coupled between the view and the game logic. It reminded me of code I would have written early in my college career. Not my best code.
After the main gameplay was done so that I could see things on the screen and touched them I looked at my code and realized how bad it was. Events tied straight into business logic actions rather than calling a packaged up set of game rules that could be tied to any front end. This means if I wanted to modify my front end to use a different widget for a particular task I would have to change my business logic as well. Not very efficient, and very difficult to work with.
It did however help me identify something that makes it difficult to learn a new language or framework: We don't always port our knowledge across. I'm very able to utilize TDD, separation of concerns, and creating elegant designs that decouple the view from the model and controller, but when jumping into a new language or drastically different platform I tend to devolve to the most simple of programming practices (which aren't good). Some practices like TDD can, and should, be applied to every project regardless of language. Having come to that realization, I'm going to restart the game that I had been working on by creating a pure backend first in Java and then tying the front end up with the Android specific stuff. I think it will both help in learning android, and in creating a decent implementation of a game.
So when moving to a new territory, try not to forget what you already know and see how it can apply to what you're doing. There is great carryover between many languages, leverage your strengths and knowledge and strive to write good code, even in your hobby.