The end result: we got there fast because we knew where we were going.
In spellcraft, this is equally important. If you don't know where you're going with a working, you are not going to get there. You have to, much like we did in our recent code project, know where you're going, and that you're going to be building toward something awesome.
In most working that I do, there are spirits involved: guardians at the quarters, and often other more specific ones. Any time I work with plants or stones, there are spirits involved - the ones that reside in the plants and stones themselves. I would be begging for trouble if I approached the spirits I work with as a clueless twit, with no idea of what I want and just say, "please, just make me happy." I know that if someone approached me like that, I'd turn a deaf ear, or worse, a mischevious ear.
Take a wild guess at how well I'd be received if I were to go before a city council with a proposal I wanted a vote on, and just said, "Well, I don't know, I just want to make the city a nicer place." Likewise, I'd be a fool if I were to approach investors for funding for my new business startup if I didn't have a solid business plan in hand to show them. I'd hardly command the respect of those people enough for them to truly want to aid me in my endeavor. Why expect anything less from spirits? There's a very good reason that many places in many grimoires warn the would-be conjurer of approaching spirits without being armed and armoured with a solid knowledge of the goal desired.
Even if your working does not involve spirits, it does not make the importance of determining your goal any less important. If you don't know what you want, how will you know when you get it? And will you appreciate it at all?
For these reasons, before crafting any spell, I always sit down and do at least one divination beforehand, sometimes multiple ones for complex issues. The preliminary divination can help me uncover aspects I might not have seen or warn me of potential obstacles I'll face. Divining is a large part of that virtue of the east, as it gives the one casting the spell the confidence that he or she is on the right course. Tarot and scrying are my preferred methods for this.
Along with divination, I'll research and plan and know as many of the factors going in to the success of the spell as possible. I'll research the factors needed for success, and explore potential ways to get there. I'll brainstorm on paper before I ever pull a single jar of herbs or candle from my cabinet.
The four virtues create a really good roadmap for magical success, and indeed, success in most endeavors that one might engage in, and to know - the virtue of the east - is the start of the cycle. With a plan in hand and the goal defined, you have taken the first step to making your desire a reality.