Reply to Synths and Producing - How do you know what sound you want?

Hey,

This is a simple thread out of interest of other peoples work flow. I use various synths such as Komplete 8, Sylenth and all of Ableton Suite's various sound design instruments. I tend to find myself experimenting all the time without any real direction or objective, to the point where i will start a production with one idea and end up with something completely different, which isn't necessarily a bad thing.
I was just wondering... how do you know what sound you want? And with all the crazy synthesis styles and parameters, how do you get there without getting side-tracked?
On top of all this, do you often use presets in your productions, or do you endeavour to avoid this at all costs?

S.