just wait people invest into it. If you see an ICO have more than 10 mil invested so you can make sure 70% it is a good ICO
What if you are late with that ? You will just lose your chance to invest in a new coin that has the potential. If you wait long sometimes the coin will increase in the value so you will just lose your money.
My way is to search everything about the ICO. Search about the team, whitepaper and the project. If they are all good and the first million tokens are sold you would be able to make a investment.