You have to build a nice designed portofoio where you list all the previous project you worked on. As you can build a website plus social media channels for the projects you partnered with, you should be able to build stuff for your service.

If this an Announcement thread for your service, then you are not in the right board. You have to post in Service Announcement board for altcoins, or if you accept btc payment, you can post this as an offer in the "Services" board. Use the "move" button in bottom left of this page.