Imagine that person doing #2. I'm being serious.

And yeah, time, of course.

i never really relate to crush problems because i usually get over them in like 2 weeks :I so i guess i think it's just a matter of time

I personally find that if they are taken, or express interest in someone else it ruins the crush for me. I think I'm personally excited by the chase of having a crush on someone. So when that's ruined for me, the crush wears off. You need to find what excites you about your crushes and find a way to manipulate that feeling so that you know there's not a chance.

Purge them from your mind and fill your thoughts with different things. Don't lurk their social media and you'll be over it in no time

What I did was:

1. Find someone hotter.
2. Get hotter than him/her.
3. Think about all the bad things about him/her.
4. Know that even though you might think he/she is perfect for you, it may not the the same in 1 year.

This might take 2 or 3 months, and also focus yourself on other things! Go out with friends, travel to places you can afford, going to the same enviroment every day will only make you think about your crush more and no change will happen.

Completely accept the fact that your crush won't like you and move on. It's hard but time will help.

Keep yourself busy as well and/or find other people.