Compliments may be given over the phone, by email, by text, and even on social media -- but nothing can compare to a compliment delivered in person. Although it may seem straight forward to offer a compliment to your girlfriend, there are actually specific ways that you can get it right -- or get it very wrong. If you want your compliment to have the best impact, always make sure that it comes from the heart, that you have no hidden agenda, and that it is appropriate for the situation.

Be Genuine

The best compliments are genuine and sincere. Tell your girlfriend how impressed you are with her snowboarding skills, how much you like her new hoop earrings, or how her jokes brighten your day -- you won't have to think too much about the best compliments because they will come naturally. Share these compliments as they spring to mind -- never hold back if you have genuine praise to offer. Compliments that come from the heart will always be well received.

Be Positive and Direct

Be sure that your compliments are not unintentionally negative or rude, advises psychology professor Susan Krauss Whitbourne, in the "Psychology Today" article, "9 Types of Compliments and Why They Work (Or Not)." Do this by avoiding the double-edged compliment, such as telling your girlfriend that her hairstyle "looks better" instead of saying that it "looks nice." Double-edged compliments will leave your girlfriend feeling worse rather than better. Compliments should always be positive and direct.

Praise in Public

Offer compliments to your girlfriend in front of other people, in addition to when the two of you are alone together, advises Christie Matheson, author of "The Art of the Compliment: Using Kind Words With Grace and Style." Compliments offered in the presence of others have an extra "oomph", not only because there are extra sets of ears, but because they show that you have the confidence to give praise in public. At the same time, avoid giving your girlfriend too many compliments, just to make yourself look good in front on other people. Doing so reduces the positive impact of what you say.

Praise Attributes

If you really want to leave a lasting impact with your compliment, offer praise for a personality characteristic, ability or skill. For example, if your girlfriend just aced her Chemistry exam, say something like, "I knew you would do well, you have a real knack for science" or "Awesome job -- you really know your stuff!" These types of compliments are heard less often and will leave more of an impression. Though the chemistry wizard would probably also love to hear that her new outfit looks dazzling -- so don't hold back.