As I'm sure you're aware, photos are a must. Good photos, not fuzzy-dark-out-of-focus photos. You
can make good photos with a cell phone...you just have to take your time and stay out of that snapshot mindset. I've seen lots of good stuff for sale...stuff I'd be interested in...but no way I'd send someone money based on some of the trash photos that accompany an ad.
I personally think there should be at least three photos per holster...front, back, and looking down into the holster. Perhaps more photos if the holster is decorated with floral carving, border stamping, conchos, whatever.
I think group photos of holsters are pretty useless and troublesome, unless you're using a photo editing program and can put a number on each item in the photo.
In addition to photos, detailed descriptions help. Tell what belt width a holster will work with. If you know what revolver or pistol works with a holster, say so. Giving holster dimensions in inches really isn't all that helpful to a lot of folks. And if you're selling belts, state the belt width and length to center hole, in addition to any other details. Don't make your customers have to guess at stuff and waste time with e-mails to find out about an item.
The fewer questions a potential buyer has to ask, the less complicated a transaction will be, and the faster holsters will sell.