Movement in your booth is one of the best ways to engage prospects. Giveaways are also popular. Such items should have little real value but considerable intrinsic value so they will be retained as a further reminder of your business and your products. Always stand because no one wants to disturb a resting person. Don't talk to friends and colleagues.
Strangers are reluctant to interrupt a conversation.
Above all, watch nonverbal messages. Keep your hands behind your back. It's comfortable and looks professional. Never fold your arms across your chest. Similarly, prospects assuming this stance may be skeptical, even hostile.