Figuring out website ranking

As you might know, one can have all the coding/designing/devops ability in the world to develop a killer idea, or a simple one. But if no one knows about it is of no use.

Can you share what platforms/techniques do you use to get organic traffic/customers? and how much budget do you put into it?

I've tried online paid advertising, but it only gives a temporary boost! then it drops to 0 again.