Know the other person:
Before going on stage, you should have a couple of meetings with your partner as it will really help you to understand his/her psyche and ultimately you won't find any trouble in doing love scenes on stage.
Do rehearsals as it is the only way to get a grip over your nerves. You should memorise the script as any fumble will ruin your performance. Moreover, these sessions will improve your dialogue delivery and you will be able to work on your facial expressions.
Do not hide your feelings:
If you are not confident and comfortable with the scene, do not hide from your partners. Just share your concerns and worries and they will really help you to get out of trouble. Moreover, your partner can really reduce your burden by handling several things on stage.
You must be in character while going on the stage. Forget about your personal feelings and start thinking with that character’s mind. Try to develop an accent and speaking style of that character. This negation will really help you to stay focused and ultimately you will be able to give it your best shot.
Be in love:
Remember, these kinds of scenes are not regular scenes so you must act flawlessly. Bring passion in your dialogues, wake your emotions up and convince the audience that the other person is the love of your life.
Do not hesitate:
Do not feel ashamed in going close to your partner. Demolish all the walls of hesitation and show warmth in your emotions and actions.
This is very important otherwise you won’t be able to earn some applause from the audience. Just think that you are the star of the show and everyone has come just to see you.