Farsthary (Raúl Fernández Hernández) made this video demonstration of his the unlimited clay modifier. The unlimited clay is a way to sculpt a mesh without worrying about underneath topology. If you haven't seen it, just check the video. If you have seen it too many times already, may be you want to support Raúl more so we could have it earlier.
From his blog post, Farsthary writes:
Unlimited clay good for:
- Fast base shape sketching for refining in multires later.
- Models with high detail concentration in relative small areas.
- Extending geometry on the fly.
Multires is good for:
- very evenly detailed models.
- refining small details in final models.
- Tinker Code (Farsthary's blog, where you can start supporting his development)