I normally get a small gift as a token of my appreciation for all the hard work that each intern brings. This intern, in particular, has been outstanding. We share a love for food and get along well.
As a team, we send each intern off with a farewell lunch. I have told him that we'll have a deferred one for him once we are able to socialize again.
Last night, I sent him an e-gift card. It seems informal, but I wrote a personalized message. It's better than doing absolutely nothing.
Luckily, we get to talk tomorrow. We have exchanged cell phone numbers, so we'll keep in touch.
I'm not sure how my team will manage without him. He has played such an important part of our team that the void will be difficult to fill, especially when we can't backfill his role.