Let's say I'm a pirate captain in the West Indies during the golden age of piracy and I want my own flag design, like Blackbeard, Bartholomew Roberts, or Jack Rackham, where and who could I go to in order to get my own flag design?
Bonus question : Was there ever a "standard" pirate flag that was popular amongst most pirates? If so, where could a pirate go to get a new one? Wikipedia tells us that this flag was flown by Sam Bellamy and Edward England, so I'm wondering if it was popular like the Jolly Roger amongst other pirates?
For all of your pirate flag history needs, you'll want to check out Jolly Rogers, the True History of Pirate Flags by E.T. Fox (you can find it on Lulu and Amazon).
But onto the question. Crews decided on their flag together, and they made them themselves. Of the three designs you mentioned, only one is historically correct (Roberts'). The most commonly described pirate flags in the 1710s and 1720s were black flags with nothing on them or black flags with a "death's head" or "death's head and crossed bones" on them (death's head is a skull). The motifs were familiar symbols of the period associated with death. I would go into more detail, but there is so much material in Dr. Fox's book that I mentioned above, so I highly recommend picking that up and learning more.