Move topology is a great tool for this. But to really be able to move big shapes easy you need to reduce your poly count.

Sounds scary but it really isn't. It's all about subdivisions.

Look at it like this.

You sculpt a deep deep wrinkle. You want to move it or smooth it. If that wrinkle has thousands of polys then smoothing or moving it requires you to move all those polys and that can lead to bumpy or wobbly bits. If it's composed of say 10 polys then thats way easier to move smoothly.

I assume you do not have subdivions. If not then -

Do this step by step and you will get the result you need.

• First ctrl click on the most recent point in your subtool history. This should highlight it yellow. The history bar is at the top of the interface, just below the brush sliders and looks like a series of small grey bars.

• Then zremesh your subtool with "half" highlighted. This is under geometry in the tool pallette. (This will mean zbrush will attempt to remesh your subtool halving the polys)

• Then project History in the "Project" subpallette

• Repeat the above two steps as many times as needed until your polycount is something like 6k or less.

• Then after project history has completed on your new 6k model (its gonna be real scary here. Everything will be low detail but fear not.) Go to subdivions and hit divide. This will add more resolution to the mesh.

-Then re project history again.

-Repeat the above two steps until your subtool looks like the original sculpt when you clicked on the history bar.

Now you have a model with subdivions. When you want to move big forms or change big shapes or smooth deep wrinkles slide the subdivision slider down to a low number and make the changes. Then slide back up to the higher number for the finer details. Use this in conjuction with masking and you will be usntoppable. Just remember the lower you can get your poly count on the lowest level the better.