Tips from GunsInternational.com on the basics of creating a listing.

1. Place no road blocks to sales.  Do not tell buyers to look for pictures elsewhere, call for a price, leave out manufacture dates, or measurements. 
2. Pictures sell the guns. Take enough pictures to place the gun in the potential buyer’s hands. No one wants returns…be sure to photograph any flaws.
3. Buyers appreciate a seller taking the time to create a detailed listing and therefore eliminating the need to ask basic questions, or worse just skipping your listing to purchase from another seller.
4. Finally, proof your listings…did they load with all the images and details.    

 
Title:  Include the Manufacturer, Model and Caliber (Minimum)
Description:  Include any features a buyer may place in a search that does not fall under the bullet point fields, i.e Proofs, Provenance, Commemorative, Condition discussion, Country of manufacture, Use – i.e. Skeet, Trap, Varmint, African Safari .
Bullet points: Minimum fields should be Manufacturer, Model, Caliber, Barrel Length, Condition and Year Made.
Price Field: Only include the current price to assist with price searches.  If it was lowered include this information under description such as was $1000 and now $900.  Price field should just be th enew price of $900
Date of manufacture is very important to many buyers, include it. Do not depend on a buyer to look it up from a serial number.   The date of manufacture is particularly important once a firearm is 50 years old, as it then qualifies as a Curio & Relic for transfer purposes.  If the firearm was manufactured prior to 1899 then it then qualifies as an Antique for transfer purposes and can be shipped directly to the buyer.  The date of manufacture is very important for Colt’s and Winchester’s in particular to properly categorize on GunsInternational.com. Many of the models, i.e Colt Single Action Army’s 1st Gen, 2nd Gen and 3rd Gen or Winchester rifles as Antique, Pre and Post 64 are dependent upon the date of manufacture.
Here are some quick and helpful links for dates of manufacture:
Colt   http://www.colt.com/Customer-Services/Serial-Number-Lookup
Westley Richards  https://www.westleyrichards.com/services/gun-histories
Winchester   https://winchestercollector.org/dates/
Popular Manufacturers - Serialization & Dates of Manufacture - http://www.nramuseum.com/media/940941/serialization-date%20of%20manufacture.pdf