We've been using X as the core-theme on our site for years now. Over time, we've made a lot of changes etc to make it look the way we want to.
However... it's time for a massive design-upgrade.
This means we're re-designing our site from scratch. Right now the design is only done in Photoshop, which will have to be turned into reality on X.
My question is... Any best practices for a smooth transition? Would it be best to create a new child-theme with the changes? And what if the changes are completely different... would it make most sense to stick with X, or switch to Pro?
Any points or insights would be appreciated.