Reaching out to potential new mentors is a great way to get a leg up on your career.

But what about when you're not sure how to start the email, or afraid to ask for help or (most importantly) worried about wasting their time?

Nicole Zhu, a product engineer at Vox, recently received an email from a college student asking for help with his career planning. She was shocked at how many questions he asked. She sent back meaty, multi-paragraph responses -- "an essay worth of an email" -- but didn't hear back. When he followed up, he asked for a job connection -- without having thanked her, or even acknowledged the effort and time her previous response required.

So Zhu fired back.

This, of course, is not the ideal scenario.

But these skills aren't taught in school. There aren't useful email templates out there (and if there are, don't use them anyway -- no one likes a form email). So how do you even get started?

"The email contact is definitely a source of anxiety for potential mentees or protegees," says Ellen Ensher, professor of management at Loyola Marymount University. "I feel like I see trepidation at all ages and levels. There's uncertainty about how to even craft that email."

Here are some tips on how to do that, before you hit send.

Do your homework

Ask yourself: Why are you contacting this person in particular? Did they go to your college? Did you meet at a conference? Are you an admirer of their work?

These are all great reasons to reach out, but not if you only found the name by googling "prominent folks in x industry."

"Demonstrate a familiarity with a person and their work -- [more than] just seeing them as a name and a connection to make," Zhu says. "That's often what makes it seem transactional, when someone hasn't really done their homework."

Know what you're asking

Think about one thing you'd want to get from connecting with this person. Is it the chance to learn more about how they do a certain thing at their place of work? Insight into how to this person crafted the career or position they now have?

Come to the table showing you've considered these questions. That will already make the person more likely to reach back out with a helping hand.

"Never say 'will you be my mentor,' but start with a small ask," Ensher says. "'I'd love to chat for 20 minutes at a time that's convenient for you' is palatable."

Don't ask them to work for free

Zhu says her response included Venmo and PayPal info -- because she only reviews résumés for free for friends, and she didn't yet know this person well enough to consider him such.

And she says she doesn't regret telling him so.

"I think you have to have a relationship with someone to ask for feedback, especially when it comes to asking for a work sample," Ensher says. "If it's just someone you saw on LinkedIn who went to your college, keep it very simple."

Say thank you

This goes without saying.

And while you're at it, offer to help them if there's ever an opportunity in which you can do so.

"It's less transactional if you just acknowledge that you're willing to be helpful to them," Ensher says. "It implicitly lets them know that you understand that you are withdrawing from the bank of goodwill and you're indicating you'd like to return that in the future. And make sure you become the kind of person who really does do that."

Pay it forward

The next time someone emails you asking to connect, think about the points above -- and pass them along to others in your network.