Please find the attached is overly used and lost its essence, this creates a sense of flaky feeling to the email body. It would be more thoughtful to alter this sentence unique to the context. People are smart - they do not like to be told!
This mail contains the proposal documents.
I've attached my portfolio.
I've kept contract documents in this email.
Please refer to the attached document for more details. (contextual)
Check for the quality of the attachment
Format, extension of the file
The reader has the software to open?
Password protected, if confidential.
Inform the reader that the email contains attachments.
Attaching huge files is not helpful. Upload them to cloud storage and attach a link.