I normally don't have a clear idea of how a figure will look when finished, or if I do it often changes dramatically during the making process. I often have an idea for a head (or sometimes feet!) and just start making. In the photo you can see some bits and pieces for 2 figures. A hose made from wire wrapped around a piece of dowl, covered in masking tape and pva and then squeezed to give a concertina effect. This looks great when attached to plastic nozzles or oxygen bottles.
There are two heads. For the first I had an idea for a character with a top hat, I'll add goggles to his hat later. Not sure about the rest of him but I fancy a victorian looking officer/pilot.
The second was originally going to be a Plague Doctor, I'd seen one in a film recently and they look great but I couldn't seem to get the beak to work with all the steam punk bits so now he will have a leather mask with breathing tubes and weird googles.