Selectors

You can use Chrome DevTools to test selector and see if they work before putting them into your program.

• To test a potential CssSelector, open the devtools console and type $$() with your css selector in the parentheses. For example, $$("[ng-if="!node.nodeListRenaming"]")
• For xpath, do the same but instead of $$ at the beginning, do $x. For example, $x("//div[@ng-if="!node.nodeListRenaming"][contains(text(), "1.")]")

XPath

• XPath Cheat Sheet 
• XPath Tester 
  • Keep in mind you can search the html tree using XPath using chromium browser dev tools.

Browser Extensions

https://dzone.com/articles/10-of-the-best-chrome-extensions-to-find-xpath-in?edition=658397 

CSS