1. Google them hard
Go all the way to page 62 if you have to. Any further is weird. Don't be weird.
2. Note down the good stuff
If I was interviewing Ellie Goulding I'd make a note of that time she played the scarecrow in The Wizard of Oz at school and try and bring it up. Dress like a wizard if you need to.
3. Notice the nuances in the song.
They love it if you can feel their music, in a non creepy way.
4. Find a way to convince yourself you're already friends.
This one time, we went to yoga (use photoshop or paint)
5. Find a way to make it go viral.
Get them to do something dead weird like stick tampons in their ears. Make sure you work it in to conversation and it's not obvious you're using them for internet fame.
6. FREAK OUT
7. Be normal.Suggest a correction