How to sculpt folded skin I'm trying to copy this model:

what tools should I use to create the wrinkles and growths on the neck? Is there a seed up the process or must it all be done by hand?
You can use the Texture panel in Sculpt Mode, as shown below:



This will apply a texture to your brush. If it doesn't look right, you can adjust the size of the texture under the "Size" portion of the panel. Additionally, you can use "Spacing" under the Stroke panel to adjust the sample rate(?) of the stroke.

Edit: Here is a video of the texture brush in action, at around 35 minutes in.