Open and honest communications are vital for any intimate relationship. That means you sometimes will leave yourself open and vulnerable in order to get what you want. Other times, you'll have to play the give and take game.
Unfortunately, we're told that if we ask for what we want, we're being selfish. I don't believe so. I call it being assertive. It's possible to assert your wants and needs without coming across as a total jerk. So, don't be afraid to ask for what you need.
If I knew your gender, I could answer easier, but the general answer is to start with talking about a similar emotional situation that the other person feels, so they are set up to relate to how you feels about a situation. Then transition by saying ..."that's how I feel when you xxxx". It takes them from just hearing your words to hearing your emotions. Good luck