Try to get listed on ICO lists and get in contact with all those ICO Review Telegram Channels if you wanna buy some reach.
The good question was lighten in this post. The very Great idea promotes itself easily. But as to my mind there are also should be a critical amount of people who know about it to spread the idea. I'm working now on a project called Ponzi Trust - and I should tell you that they have an explosive idea, with the using of smart-contract and blockhain technologies in a very new and modern manner. It only needs a very good promo team with certain media focused, I think.