I have played men's singles and doubles for many years and have enjoyed playing both immensely. I also equally enjoy playing mixed doubles. However, there are certain strategies and tips that you should be aware of when playing mixed doubles.
Getting along with your partner is probably the most important aspect of mixed doubles. Since I stand almost 6-feet-6 inches tall, I can be intimidating to my partner, especially if she is only 5-1 or 5-2. That being said, the physical make up of each player really isn't that important. Most important, you should be supportive of your partner at all times and should never be critical of their play.
If you're having problems communicating with your partner, and its evident that you aren't getting along, it would be a good decision for both of you to find a different partner. Playing tennis is important, especially if you're using the sport as a fitness tool, but not at the expense of your partner's psyche, whether your partner is a man or woman. Criticism will be mentally and emotionally draining for both of you.
After you have selected a partner whom you enjoy playing with, you should discuss what your team's strengths and weaknesses are, giving both players an equal opportunity to share in the discussion. Problems should not arise because one player may be better than his or her partner.
If you are aware of this, you will be much more decisive as to who should serve first. You should also decide which player will play the forehand or backhand side of the court. The player with the better backhand usually plays the backhand court. He or she would be taking most of the shots. Usually, during critical points, the player on the backhand side will be receiving serve.
That is not to say that the player on the forehand court is any less important to the team. They should be able to hit deep returns if the server doesn't come to net. Conversely, they should be able to hit low shots or lob if a player on the opposing team approaches the net.
If a player has a liking for one side of the court, it would be smart to let him or her play on the side where he/she feels comfortable.
When either partner is serving, the player should strive to get the first serve in. This will take a great deal of pressure off the server because there's no need to worry about double faulting on the second serve. Serving with spin or slice is much more conducive to good play, than trying to hit the first serve as hard as you can. The reason the spin serve is the optimum serve to hit in mixed doubles is that it allows you to follow your serve to the net. A spin serve clears the net higher than a flat serve and gives you a greater margin of error.
Some players take advantage of an easy second serve and hit it as hard as they can at the server's partner at the net. This could result in extremely ill feelings between both teams. The other reason I feel it is wrong to hit a hard shot at the opponent at the net is that the player may not have the tennis skills to return a shot or get out of the way of a shot that is hit right at the player. You could also seriously hurt someone by using this tactic. In addition, we should be playing tennis for fun, not to hurt someone.
I can't stress enough how important it is for both partners to be able to play net.
If you are apprehensive about playing net, you could take a few lessons to work on your net game. Once you become more proficient in your net play, you'll find that it is really enjoyable playing net.