Many ideas and opinions can be used for successful ICO. But each concept must be realistic and usable. If your project is based on a real-life product or service, it will attract more investors. Moreover, you must have a definite future plan and it must be transformed into reality. And you must work hard on the project and work on its development. If people can accurately gather information about the future potential of your projector and its token of use, it can be a success.
The problem is most investors are already disappointed with blockchain projects so right now, to be successful in raising funds is like punch in the air. Unless, you are truly backed by famous companies. I think, there's no need to ask how you can be successful in handling ICO but rather look for potential big whales that are willing to finance your project. If you believe you have novel idea here, pitch it to them and if your foundation is rock solid, I don't think they will say no.
Yes, even if how good the idea of the project, there is no point if there will be no investors to come. Investors are already avoiding the crowdfunding as they don't make any profit from it. Agree from what you have said, unless they have someone in their back that can support their project to advertise to big investors, as long as they like the idea of the project, they will become successful.