I use paypal. I do not charge a fee for paypal since it is my preference for my clients to pay their deposits through paypal. If I had a better/easier way of accepting payments that didn’t charge me or my clients a fee then I would maybe consider charging one for using paypal.
You could consider asking your clients to select the “gift” option when sending a payment instead of you sending them a money request. No fees are taken that way. But with so many people not knowing how to work paypal very well it would be a bit of a hassle in my opinion.