What you need is a Universal Button designed, created and supported as standard. We accept all payments type thing including Cryptocurrency. It could be a circle design with mini logos of all payments making up the circle. A universal symbol/logo for all Cryptocurrency should be designed and included. Im fed up with just seeing the Bitcoin logo (Which is bound to be fought over by big greedy Bitcoin people) being used to advertise acceptance of crypto.
I love circles, so make it round;)