Initially, through YouTube channels or through users with good number of followers, a project be it upcoming or existing can be promoted to a larger audience. But overtime, it tends not to be enough thus leading to more of Airdrops, bounties etc. So as a new coin, the first thing is, checking your budget and what you can afford to spend on promotion then going with it. You have to promote first before you can think of selling, this is to make people aware of what your project is all about.
Secondly, once the project is being promoted the team is meant to be working hard as well; if it's to have an MVP or to showcase what is already developed.
Then after a stipulated time, the team can look for an adequate exchange to conduct their IEO, ICO or as the case maybe. If they have their own funds they can still list on adequate exchanges.
Lastly to make the project worth it, the team have to keep developing.