You’ve been doing music for a while. You have a professional act. You perform occasionally but you haven’t gotten paid for your performance, then it happens someone wants to pay you for a gig. Maybe someone wants you to perform on their CD or project and you want charge a fee. How much do you want to charge for these shows and performances. The first thing you need to find out is what is the going rate is for shows in your area. You might just want to ask around and see what the going price is. Talk to other musicians and studios to see what people are charging for the services. Always look at who is trying to hire you. If you know their budget, you will know how much to ask for. if it’s a corporation they probably have more money than a single individual.
Learn about the show that someone is trying to hire you for. Learn the specs of the show to see how much to ask for. Always ask for more than you want and negotiated down form there.