Love is something we all experience in one way or another. Some of us don't feel romantic love and are fine with platonic love. These people are not broken nor are they going against nature, as some might say. Others of us express our romantic feelings through our actions, thoughts, and interactions with others. There is no right or wrong way to express your love.
First, love is expressed through our actions. Whether it be hugging or even just listening to someone. You can show your love through the little things. Such as a friend listening to your rant and then helping you through your emotions. Or a couple who help each other whenever they need it. If you truly are in love with someone your actions will show it. It could be taking someone to a concert of their favorite band. Or doing something they love even though you don't really like it. For example friend A loves XYZ band. Friend B finds that band kinda boring however they still make sure they know things about the band and always goes with Friend A to concerts. Friend B's actions of keeping up with the band show that they do love their friend.
Love also has a lot to do with feelings. Feelings are felt by different people in different ways. Feelings are intense for some while duller for others. I like to think that those who have love a first sight experience more intense emotions on a daily basis. Your emotions are in a way connected to that person or persons you love. And vice versa. When you are around those you love you may feel very comfortable, safe, and/or butterflies. You may notice that some people feel nothing when something happens to someone they love. Do they truly love them or is their relationship more what could be described as a business relationship? These are the questions to ask when it comes to this aspect.
Sacrifice is involved in almost any relationship however it is especially important in personal relationships. In my opinion, the strongest love will sacrifice its life for the other person.