It is very easy to make anything trend on Schooln.ng as the algorithm favours contents or gists with good enough engagement. Be it your business, your hot gist on your school campus or you're running some awareness campaign or online protest of any sort.
There are 2 ways to achieve this:
Choose a keyword or phrase for your content or gist and employ different ways to make your peers upload gists and content using the same keyword or phrase. Choose a #hashtag and use the same method above to ensure multiple gists or contents are uploaded using the same #hashtag.