How do founders make money from ICO?

I'm curious to understand the mechanisms behind how founders actually make money from Initial Coin Offerings (ICOs). Could you elaborate on the various ways in which they capitalize on these fundraising events? Are there upfront fees or commissions? Do they profit primarily through the appreciation of their own tokens? Are there other avenues of revenue generation that founders typically explore with ICOs? Additionally, is there a standard percentage of profits founders tend to retain, or does it vary widely based on the specific project and its needs?