Protecting and Sharing a Sensitive PDF

Lock it with a password, mark it confidential, and keep the file small enough to email.

A password comes first since it's the actual access control -- everything after this step assumes the file is already restricted to its intended recipient. A confidential or draft watermark is a visual signal on top of that access control, reminding whoever opens it (even the intended recipient) how the document should be handled, which a password alone doesn't communicate. Compression stays last since it should never come before the password and watermark are in place -- shrinking a file doesn't undo mistakes made in the earlier steps, but doing it last avoids re-processing the file again after.

Each step opens as its own tool -- download from one, upload into the next, same as any free tool on the site.