InDesign

If packaging from InDesign, save the final file. Then go to File > Package. Use these settings:

Photoshop

If packaging from Photoshop, place the layered PSD file in a folder with a PDF for proofing. Include any linked files in the folder, or rasterize linked files in the PSD (right click layer > Rasterize Layer)

Include PDF for proofing. Use these settings when saving PDF from Photoshop: High Quality PDF, do not Preserve Photoshop Editing Capabilities. File size should be under 10MB.