[ebj73]

Yes, it's important to develop a habit to plan ahead before coding. For anything bigger than small scripts or utilities, you need to do this.

On the other hand, there's the eternal conflict between the waterfall model and the iterative development model. The waterfall model dictates planning (almost) everything ahead, while the iterative model says plan sufficiently far ahead, then start coding, then take a break and re-evaluate, do some more planning, do some more coding, rinse, repeat. I certainly prefer an iterative model, and building prototypes, as you do. But even then, I'd say professional development work is 90% planning ahead, and only 10% actual coding. Probably even less.