you can start by searching first for upcoming projects and go through all of their websites. Usually you visit a website that lists all upcoming ICO's, these websites have links to the project's website and there you find the whitepaper and all the information relevant to what the project is about. If you like the main idea you can start reading the whitepaper and understand what the project is trying to offer or what issue it is trying to resolve, once you've read through everything, search if there are any competitors that are in the same industry as that project, and check whether there will be any future demand for that product in the future (you can check market trends) these are all extra stuff. Usually when an ICO is good you know within the first few minutes, and these are the projects you should focus on.