Ask for a spreadsheet and a real spreadsheet comes back.
Your assistant builds spreadsheets, documents, slides, and PDFs, then emails them to you as attachments.
Files you can open and send
You get real .xlsx, .docx, .pptx, and PDF attachments you can open, edit, and forward like any file you made yourself.
Give it the raw material
Forward the conversation or attach your files, and your assistant pulls what it needs from them, plus its own research, to fill the document in.
Revise it by replying
If the first pass is close but not right, reply with what to change and a new version comes back as another attachment.
Skip the blank page.
Describe the file you need in an email and come back to a first draft.