1. Set a theme.
Hosting a Harry Potter dinner may not inspire your not-so-foodie friend to step up the hummus she's picking up from the store, but others may surprise you with homemade Butter Beer or by sporting a pair of HP-inspired glasses. A loose theme kind of breaks the ice in advance and makes it all more fun (it is a party, after all!) And a theme can also help pairing dishes.
2. Have guests commit to a course.
The cardinal sin of potluck parties is a dinner table loaded only with three kinds of hummus, four salsas, and chips. To make sure a number of different dishes show up, include a line in the invitation asking friends to reply with what they'll bring. Or once the responses have come in, ask several friends to bring a main course, salad, appetizer, or dessert. Someone will always change it up at the last minute, but at least having an idea of what to expect makes an actual meal with courses more likely.
3. Have backup dishes ready.
As the host, it's easier to pull together the main course and having a roast chicken or lasagna at the ready helps bridge any gap in courses or not having enough food. And since you know each guest will at least eat what they brought, it's a great opportunity to try out something a little different.
Do you throw (or participate in) potlucks regularly? What are your best tips for a great potluck?