Email - For small files you can please send through email : sales@chinaprinting.cn . 
Website - https://www.wetransfer.com . Large files can be uploaded to WeTransfer . They will send us a link after your uploading and we download the files from the link .
CD / USB - You can also just give us the CD or USB if you plan to come to visit us . It would be great for face to face communication . Or it can be sent by express or post if necessary .
FTP : If you have your own FTP ,we can download it there .