In Full Studio, keep photos, text and brush work on separate layers. Name layers by their purpose and reorder them to control what covers what.
Use layer visibility and opacity to compare changes. To hide an area without deleting pixels, make a selection in the Selection & smudge panel and choose Selection to layer mask.
The native Full Studio JSON project preserves editable layer masks. Keep that backup before PSD export: PSD uses raster layers, and imported or exported advanced features may change or be baked into transparency.