There are many ways to get referrals. All methods involve some work; some involve more work than others. After creating a pretty solid active referral base though, the work load does diminish. So, without further a-do, let me present you with some of the main methods used to gain referrals (With no particular order):
1. Create a Website or Blog
Creating a website or blog is an excellent way to gain referrals but also involves the most time & work.
What you do is basically set up a blog or website, create original content having to do with money making, CashCrate or something similiar & post your referral link all over it. Of course, in order to get a good amount of referrals your blog or website needs to get a good amount of traffic; More people who view your site = more clicks on your referral links. Here's a post on the CashCrate forums that tells you how to get traffic.
2. Post on Forums
Add your referral link with a description such as "Earn money online!" to your forum signature and post actively in forums such as money making forums. Just make sure not to spam.
3. Write Online Articles
Write articles about making money online, or about CashCrate & post your referral link or blog/website link . A good site that explains this in a bit more detail can be found here.
4. Flyers or Posters
Create attractive flyers or posters with your link (preferably your blog/website link) advertissing money making & post them wherever you're allowed to, such as bulletin boards.