Determine how you will organize the items you plan to sell so you can match pictures with listings with the actual item.
PC numbers work great for me. Each postcard has a PC number. Starting with PC001, I now have pictures up to about PC2800.
When a listing is typed, the title of the item starts with the PC number. The item PC number in the title helps to locate the item when it sells and needs to be sent.
When the description is written for the title, a scan is made of the postcard (s) so a picture can be added to the listing.
The picture file number is the PC number. So a scan of postcard PC001 will be pc001.jpg I also have folders for each 100 postcard scans to make finding them easier. See a list of my scans for postcards numbered PC100 through PC199 HERE.
The cards are the filed in numerical order. How original that is.
When an item sells, a record is made of the sold PC number. About a month after the item is sold, a different item is listed with the PC number. The PC numbers get recycled over time. The same boxes can be used to store the postcards. When a new card is added to the store, it is put in the numerical order box for ease of location when it sells. And on and on.
Now all of this takes time, and effort. You may find a system which works better for you. Well have at it. Develop a system that works for you. The important details are to have as many items in your store as possible, don't sell the same item more than once, replace pictures and descriptions as postcards sell, and be able to find and send an item when payment is made.
Click on these hyperlinks to visit the main pages of this OldPostcardsForSale.com website:
Find items of interest to buy in this book rack from Amazon.com:
Old Postcards For Sale 2006-2011