Now when a sculptor starts a new piece he or she will sometimes jump in or do some sketches on paper, but not many try to figure it out in the round and even fewer use sculpting as a exercise that we can scrap just like a piece of paper. Everyone has this idea that when you start sculpting a piece that you have to work it and finish it like a masterpiece, but i don't believe in this. I think it is very important to work on smaller pieces for the sake of an exercise and know from the beginning it is just a sketch. You should be able to get to a satisfied point of the sculpt and have no problem completely changing the piece or tossing it all together because the knowledge you gained is more important.
What i do is i try to do a warm-up sculpt everyday before i start working on projects, this helps to get me energized and excited and also frees me up to open my mind and work my imagination. I set aside approximately 30 min - 1 hr to do this so that i have time to create something interesting, but dont spend too much time working too much into a piece that i might not like. Its also great to do specific exercises like forcing yourself to work on a piece for 3 hrs or working on likeness, portraits, anatomy etc. When i did the 3hr exercise i started off with a concept i wasn't crazy about and forcing myself to keep at it made me really figure out why i didn't like it and fix it.
Here are some examples of my warm-ups