1. Keep it simple
There is no harm in a good theme, but keep the decorations to a minimum. I know that theme-appropriate $20 table cloth may seem life-changing, but in the grand scheme of things, a great dinner party is about conversation and food. Go ahead and choose the plastic table cloth, $0.50 tea light candles, and your personal mismatched flat wear. As long as your guests are pleasant, entertaining folks, no one will be judging.