I see a lot of listings come and go on XMR marketplaces (xmrbazaar.com, former moneromarket.io, forum posts, etc), a good chunk of them absolutely suck and are very undesirable-looking. Here are some basic tips on how to increase your chances of getting customers.

1. Include a picture in your listing. There is no reason why you should ever omit an image for your listing, even if it's a service or a Wanted listing. It's the most basic way to get attention, and shows your potential customer what the main idea is. Not including a picture shows that you're sloppy and lazy. No one wants to do business with that.
2. Provide more details on how the interaction is expected to happen. A 1-2-3 bullet point list, or small paragraph will do. I cant tell you how many listings I've come across, even by longtime sellers, who post vague, lazy descriptions that don't really tell me what I can expect in detail or how it will go down. A customer who doesn't know what he is getting often won't even bother to reach out with questions, because people don't want to do your work for you. Give the people ALL the info, youll increase for chances of interest.
3. Provide at least one external mode of communication. SimpleX, Session, whatever your favorite messenger is. This shows that you're serious about completing business. And the built in messenger kinda sucks and is not as convenient, let's be honest. I love seeing a SimpleX link in someone's bio. makes it so easy to have a conversation with them, which increase the likelihood of me buying from them.
4. Put effort into your profile. Put a damn profile pic for Pete's sake. Write a bio. Do one small trade with a veteran seller. I see a lot of interesting listings come up, but so many of them are by a brand new account with zero trades, no profile pic, no bio, no links, nothing. It's an instant turn off because I have no idea what to expect from them.
5. Use escrow. even with all the above tips, a new seller with one or zero trades is still a bit suspicious. use escrow for anything above a small amount. Once you build reputation you can forego it more and more.

Hope this helps :)