Conversations strokes (like your tennis strokes) can be short and simple or deep and long. If you conversation is shallow your relationship with the person you are talking to will likely return shallow or non existent volleys. The deeper your conversation will create an opportunity for more enriching "conversational play".
For those people you love the most, practicing deep conversational strokes will provide you a more satisfying and pleasurable conversation. There are risks in hitting a tennis stroke deep - it could go "out of bounds" or be interpreted as a ball not to be returned. However, in most cases your conversational player will see the effort you are putting into your stroke and attempt to return it deep also.
Here is a deep volley question: "What made you feel good about yourself today?" Notice how it is an open ended question; it is very personal; it is positive; it indicates a sincere desire to learn more about the feelings of others.
I suggest you try some "deep volleys" first with your spouse, parents, brothers and sisters and then "graduate" to best friends (caution is warranted here - be sure you know what a best friend is).
Remember, hitting it deep means more challenging returns - but a more enriching game.
Credit for this entry idea: Six Questions that will save your relationships by MarcandAngel.com
I suggest you watch the video that they put together on their blog site.