A long time ago, in a land far, far away, an established escort gave me this when I asked about taking credit cards.He gave me the form you see here to imprint credit cards (...credit card companies want to know the card was present.) and gave me the attachment to have the client sign in case there was a charge back.
I don't advise it and there are only a few times in my escort life that I may have taken them. I can't think of many reasons that there is not a way around it, but there may the time that it's the preferred way for someone to pay for your time.
My advice is unless you have a high volume and it's really worthwhile for you, encourage the client to use another form of payment.I can argue with myself that even one payment is one payment more than I'd have otherwise, but the risk and work you have to do with it for a one-time payment, is more likely more headache than you are going to want to deal with.
Remember, just like anything online, it's track-able. If you do it online, there is a record.
This day in age there are so many ways to process a one time charge online though it does seem tempting.
PayPal does not accept anything of an adult nature. Find out more in the PayPal Acceptable Use Policy - Mature Audiences.
HERE is a resource should you want to take payments online.
Sometimes you can use your own online banking to send an invoice to one person.
