Question #1: How do you learn to communicate better with a boyfriend/girlfriend? Spouse?

Part 2 - Boundary Setting:

The second concept that I believe is helpful in improving communication is boundary setting.  Boundary setting applies to all aspects of a relationship - but it is particularly helpful when there are difficult conversations with the other person.  Setting boundaries is primarily for you versus the other person. When you understand that you have control over how you respond to situations, words and/or another person's actions - it can be extremely empowering.

Think of boundary setting as your personal property line. Your neighbor cannot cross onto your property and enter your house without your permission.  So it is with setting boundaries - another person cannot hand you their anger unless you willingly take it upon yourself.   For example: just because the other person decides to get upset with you - you can choose how you will respond.  You can decide to get upset with them as well with an "I'll show them" kind of attitude; or, you can decide to allow them (and you) time to cool off and stay in a positive frame of mind until such time that you both can sit down quietly and discuss the matter.

Boundary setting is about self-control and taking ownership for your own life. It is also about loving others without enabling; or rescuing; or allowing yourself to take on unnecessary guilt.  Typically, lack of proper boundary setting and anger go hand in hand.  Each person must decide to take responsibility for their own attitudes, actions and behaviors. Then ultimately you should choose how you will respond -
so choose wisely.

See Cloud & Townsend, Boundaries in Marriage.
http://www.marriagebuilders.com/graphic/mbi3200_love.html