I personally look through some sites with ratings from time to time. But I don't completely focus on them because not all ICOs with high ratings are guaranteed to be successful. I rely more on the team, the telegram, wp and so on
If you want some advice: rely on the team mostly. Check whether they are awesome if you can and whether they do strong public pitches. Rating agencies are very questionable.
What if you do not know much about all this? And can not understand wheather it's a good team or not?