Are there any time sensitive looksmaxes at 19?

[ETR]

I know that there are things you can do when you are developing/in puberty to looksmax that wont work later on but is there anything that will work at 19 that wont work later on. I missed out on being able to take advantage of my puberty but I want to make sure there isn't anything that I should be doing right now that I wont be able to do later and get similar results

 

[cargo70]

This would be a good idea for a megathread of time-sensitive looksmaxes. Compile a list of them all and go into detail.