When to start college applications?

I am an incoming senior in high school and was wondering when the best time to start college applications were? What parts can you start in the summer and which parts do I have to wait for? Please answer, any and all help is greatly appreciated!

The Common App opens August 1 and can be submitted then. The essay prompts have been out since January and will not change for this application cycle. Here they are:
https://www.commonapp.org/whats-appening/application-updates/2018-2019-common-application-essay-prompts

You can, and should, get that essay done over the summer.

Yep, definitely work on your essay for the common app. If there is a school you are targeting that has supplemental questions, keep an eye out for those coming out. If any of your school or your teachers ask for a form to fill out for references, you should probably be working on that now if you haven’t already. It wouldn’t hurt to work on your “why _insert school essay” for your top schools. Even if they don’t require one, it can help you formulate your overall application picture, help you sort out your thoughts, and would help give you a start on interview preparation.

Good luck!

If you get all of those assignments done, consider whether scholarships would make your college life easier. If so, start looking at scholarships and working on their essays.

A college often won’t look at your app until they get the app & any payment, transcripts if they request them (sent by your school), any required recommendations, and test scores if they ask you to have them sent. Work on your essays, and work out your list of activities & awards to put in the Common app.

Even if the Common App opens Aug 1, occasionally schools don’t get updates to their supplemental essays into the Common App right on Aug 1.