Cunning trick to make a mirrored copy of your sculpty right there in Blender…
Shift + D to Duplicate your mesh
Space bar -> Transform -> Mirror -> <choose axis>
If you need to do this a lot there are even key strokes for it: Ctrl M + <X, Y or Z>
I vaguely remembered this from the tutorials that I did when I first started with Blender, but it was buried pretty deep until I heard someone mention it in a conversation yesterday. It’s a great example of why I keep saying that you just can’t do/watch too many Blender tutorials. Don’t just do the sculpty ones, watch people modelling with Blender on YouTube or somewhere. Blender is an amazing tool and there are hundreds of useful tricks.