A little trick up Julia's sleeve is the copy-cat technique. Don't worry it's not as ridiculous as it sounds!
Julia says: "If your date smiles, smile back. If your date shows affection, show affection back! Your date will be looking for reassurance and if you copy his gestures, he’ll know you’re both on the same track which will make you both feel more relaxed."
Obviously don't be too overzealous with this, you could borderline on looking like a total weirdo.
But a little bit of subtle body language will go along way.