Suppose you have an existing email and don’t want to set up a Gmail just to use something YouTube or sign into google for any of their other services. You can use your existing email!
Visit this link: https://accounts.google.com/signupwithoutgmail
Enter your information using a different password, as this is a new account. Google will send you an email to confirm your email and then you will be good to go on using your work email or personal non-gmail account to access Google services!