What’s the best way to choose a display name for my Amazon Seller account?

First thing is to avoid any similarities to real or existing stores, i.e, calling your selling Amo Zan or Beast Buy. Not only does it sound phony and unreliable, it appears cheap and reflects on you that you're not willing to invest even in a name. Your display name should reflect authenticity (so try and avoid using names such as "HonestEd" or "Genuine Genie," which can point out to the exact opposite) and, if possible, be related in some way to what you are selling. For example, if you're located in Houston and you sell BBQ equipment, your display name might be TexBQ. Or, if you sell books from California, you might display Hollywood books. On the other hand, another factor to consider is this: do you plan to add different items to your store? for example, if you want to add plants to your BBQ business, you might call yourself TexSeller. Make the name easy to remember, try to stay away from complicated letter/number combos or anything that sounds negative or shady, such as unknownseller123 or buyfrommeorelse.