Learn how to use Dynamic Topology Sculpting in Blender
The dynamic topology system in Blender allows for a much more organic, creative sculpting process. It gives you much more flexibility in not only how, but what you sculpt by not limiting you to the original starting basemesh.
When working with dynamic topology, Blender will automatically tessellate the mesh under your brush stroke to account for the detail needed. This gives you the ability to add detail anywhere you wish, create new forms, and work with a much more optimized polycount since the tessellations are localized.
Check out CG Cookie Citizen for more sculpting training
To learn more about using dynamic topology in your workflow and creating finished sculptures I recommend you check out Kent Trammell’s training series on Creature Modeling For Production, and his Citizen course on Hard-Surface Sci-Fi Weapon Sculpting.