Spell craft is tricky. You have to balance flow with word choice. I am going to say that you should probably just try and see what's best for you.
The two major parts flow and word choice. The power and magnitude is really up to you to preform, but with each variation it might be easier or harder to do so.
The real trick to writing a spell is to judge what it is for. If it is a one time use spell then whatever floats your boat, but if you plan to put it in your longe time collection then you should put more effort into it.
Long story short just practice what you think is best.