Make sure to set clear expectations about what you want the mentee to do - don't leave things under-specified, due to the time difference and remoteness, it's easy to have things lost in translation. More so when there is a language barrier.
Make sure you have clear communication preferences discussed, e.g. messenger, email, slack, whatever you prefer.
Time difference: Make sure you schedule check-ins at a time that is within reasonable hours for your mentee; and try to have regular overlap with their waking hours.
Make sure to be responsive. If you're going to be temporarily busy or away, be sure to let them know.
Periodically check-in over messenger/email and ask how things are going, even in between a week. Don't let things bubble up till the end of the week to figure out things are going wrong.
Your mentee may have limited experience with good software engineering practices, writing clean code, or how to send proper pull requests, etc. The training will help with that, but be ready to provide advice and support on the basics.
Help improve their problem solving and communication skills: ask them to describe their technical approaches first - you can sanity check them and provide advice, and they also get an idea of how to communicate their changes better on pull requests.
Offer to help review a draft of their code / pull request early. They can use Pastebin or something similar. Offer tips based on the code. Mentees are often scared of making that first jump and this will make it easier for them.
Always encourage your mentees. Making a real-world, public contribution is a big deal and words of encouragement really help.
Talk about your company's engineering culture and practices - folks are eager to learn and improve.
Encourage mentees to form communities and get to know each other. We have found in the past that mentees formed their own Facebook groups and helped each other out with both technical and cultural issues (like how to work with mentors); making everyone's experience better.
- Make sure to leverage and get help from other mentors. When you're faced with a tricky situation, ask other mentors (and program admins!) for help as to how they'd solve it.