I think the ICO should have some supports from experienced team members or advisors. And you can hire a bounty manager to have a bouty campaign. Just like making ANN thread on this forum.
A great ICO should have a professional team that worked hard over the past few years and known for every ICO they have made in the past. Specially the development team and the advisory team, you can look up every one of them by doing some background check so that you're project will become successful in the future.