So here it goes:
1. Say I love you at appropriate times. IE- don't confess your love with your mouth full of beef wellington, when you are breathing nasty morning breath into their face, and don't say it after you crack a mean joke. An appropriate time might be: on a love sac, watching the sun go down, when you have a dozen roses in your hand, after finishing the best hot dog ever, or before you go to bed.
2. Facial expression are important when you are confessing your love. Never ever ever say those three special words when you have your ugly face on. Try to reserve your confessions to times when you have a composed face: a smile, a wink, pursing lips, even a half smile will do. Just as long as it melts your special someones heart.

4. Learn how to express those three magical words in different ways. TI AMO, TE QUIERO, JE T'AIME, ICH LIEBE DICH, IK HOUD VAN U, I LOVE YOU. But what ever you do, it has to be capitalized or said it great emphasis so that the person you are confessing/expressing your love to knows that you mean it.
5. And last, but certainly not least, don't forget the I. You want that person to know that it is you that loves them, not the infamous they, or your cute wiemaraner...the point is to proclaim your love like William Wallace proclaimed his freedom. Be strong and proud and be...lovable, so that your certain someone will know how to say they love you back.