One way is through material expressions, like giving flowers, jewelry and other presents, or taking them out to dinner or a night on the town, he said.
Another is through physical expressions, like holding hands, touching, gazing into another's eyes, spending quality time together and sexual contact, Abel said.
Others express love verbally, he said.
It can be overt, like speaking the words "I love you," Abel said, or subtle, by giving encouragement.
There are emotional expressions, like showing loyalty and validating another's feelings, he said. And there are thoughtful expressions, like leaving little notes or thinking of a creative way to make your partner happy.
For someone who comes from a background of physical expression, gifts - no matter how expensive - might seem cheap and repulsive, Abel said.
But spending quality time together, gazing lovingly into their eyes, might be the perfect valentine "gift," he said.
"The best advice I can give is figure out what loving style your partner is and figure out how to fill those needs," Abel said.
At that same time, you should communicate your needs, he said.
Abel's Web site is at (http://www.relationshiptools.com).