Try this with your friends. Next time you have something sincere and heartfelt to say to someone, try saying it while poking them violently in the chest, arms, or shoulder. Say it like you mean it, but poke them while you say it. Make sure to poke hard, too. And maintain eye contact.
Observe what the contrast in what you're saying and what you're doing does to the entire interaction.
Let me know how it goes.