In order or rather before starting your project I think the first thing you need is dedication, that is, you need to be dedicated to the cause, this is actually why many projects with good ideas will work up till a moment then come crashing; it was not easy for most projects but because the team are dedicated they pulled through. Also, you need to set out a budget on what you will want to spend at the onset before going for funding if possible, and most importantly you will need to surround yourself with developers or programmers who believes in the same idea with you, this will make them put in more effort to ensure the project survives. Also, you can consider having a telegram group, where you will share your ideas and allow the community to cast their interest, suggestions and so on, this will help you shape and sharpen your ideas even more. It is true that Ethereum blockchain is better for many upcoming projects, but I think you will need to make that decision with your future team, some who considers fees might go for other blockchains but those who don't mind but really need an efficient blockchain goes for Ethereum blockchain.
Lastly you might want to have an MVP (Minimum Viable Product) first before embarking on public sale if need be, this will also help you explain to people what you are working on.