New to the US: how I built my credit score to almost 800 in a year

when I moved to the US, I didnt have a credit score. the best tricks I found to boost my credit score fast were:

• rent reporting: blew up my score by 42 points. and it's free

(but I still think it's weird you can use your rent payments to boost your credit score...)

• getting 4 credit cards early on: I really use only one of them. Still, my score jumped about 10-20 points with every card because they increase the total credit limit I have
• optimizing when I pay my balance: When I forget to do this, my score goes down to 740-ish. When I do it, it jumps almost to 800, from one month to the other. Pay down your balance a day before your card reports to the credit bureaus. Easy!

I'm building a startup helping newcomers to the US set up their life (it's free). I've collected all the tips and tricks of building a credit score from scratch in a community guide (see first comment)

Feedback very welcome. And please share your own tips here!