What is the best way to earn the most out of putting money into CPF? Should we even put into CPF or start looking for alternatives such as insurance plans for retirement?

Anything but investment linked plans. I believe in transferring funds from OA to SA to maximize the earnings and the interest rates is quite good compared to banks outside unless you're good with investments (I'm still learning!) Also you can consider passive income generations. There are some retirement plans which our fellow forumers who are in the industry may be able to help!

Do not rely on cpf solely for retirement. It is always good to have alternatives. You can also learn how to invest yourself. After u grow ur wealth, you can use dividends for your retirement.