When in Zbrush, you first create a morph target before you sculpt, then sculpt and use masking and the morph target brush to reset the area of one side to original shape then send it to CC4 and apply. You do the same for the other side, it's not too hard. You can duplicate the default character to create a library of morphs. Also when you export it's important to note the "match zbrush model scale" is essential for using Symmetry brush otherwise without it, it will loose it (you did apply it) If your symmetry for some reason needs to be corrected, you can mask the good side or area you want to mirror and go to deformations and choose "Smart ReSym" -just some helpful info I wish I had known in the beginning that saves you time and fixes problems.
Thanks :) i have also used this method and works well but just found the blender method to be a bit quicker, also the blender way can be used without zbrush for anyone using edit mesh
This video shows how to split up a morph into left and right. With a custom model it doesnt have the option in the Facial Profile editor to mirror, so this is a work around, if you work on the whole face then remove the morph for the left or right side in blender, it allows you to get a mirrored morph for each side.
Yeah we can make custom face morphs for any character :) if you send us an email to info@digitalpuppets.co.uk we can send you some info on how we can help :)