The easiest way is to share your username / password with your client. Upload the files to your account; then your clients can logon as the same account to download files.
For better security, you can upload your files to a folder and then click on the Share button to share the folder to your client. You can share a folder to a DriveHQ member(s) or to a non-member(s).
If you share a folder to a non-member, you can enter the other persons' email addresses in the share-to field. After you click on share, it will ask you to send a share notification email, which contains detailed info about how to access the shared folder.
If you share a folder to a DriveHQ member(s), you can enter the user's DriveHQ username or registered email address in the share-to list. The other user can logon his / her own account and access the shared folders in the special virtual folder:
\DriveHQ Share\YOUR_USERNAME\SHARE_NAME
If you want to modify an existing share (e.g. add / remove a person in the share-to list, you can go to the Manage My Share page.