Email your text to me as a Word document, or in .lyx format for those using LaTex.
I will then work through your document, using 'Track Changes' to show corrections and inserting comments where necessary (to explain any changes which may not be obvious, to give you alternative wordings from which to choose, or to seek clarification where it has been difficult to be sure of your meaning).
Your revised work is returned to you by email, and communication continues via email if you wish to discuss any of the changes, suggestions or queries.
You have ultimate responsibility for your document. The changes I make are suggestions, and it is your choice whether you accept or reject each correction.
My task as a proofreader is to improve the language and structure of your text. For ethical reasons (and because I am a generalist with no qualifications in your field), I cannot make changes that materially affect the content of your paper.
Because I can only work for one client at a time, I cannot be available for your work "all day, every day".
It is not always possible to accept very urgent work. If you provide notice that an urgent job is coming, I can usually keep time clear for that job.