Package
InDesign and QuarkXpress can collect all the assets of your design. This ensures we receive all fonts and linked images.
InDesign: goto File,
then Package
QuarkXPress: goto File, then Collect for Output
Compress/Zip
Compressing or zipping your files protects them from any data-loss during the internet transfer.
Mac: hold Command, click the file or folder, choose Create Archive or Compress
PC: Right-click the file or folder, select Send To, then Compressed (zipped) Folder