Doubles is great, but more about placement than power and depth. Keep it away from that guy/girl at the net and try to get yourselves to the net first. Use lots of topspin to keep the baseliner at the baseline. Be careful using slice as the ball will move slower and allow the volleyer time to rush across and pick it off.
Take 25% off first serves and aim for consistency. Down the middle gives less opportunity for the returner to find a nice angle (meaning your partner at the net can move to a more central position), and serves into the body work well too.
Communicate - keep your partner geared up, don't be dismissive if he/she makes a mistake. Keep talking, maybe use some sign to let your partner know that you will "stay like a rock" or "fly like a bird".
Play percentage tennis at the baseline, but also keep moving if at the net - if you move across to take on a volley and you miss it, don't worry, carry on doing your thing.
Be careful playing lobs, for some reason people who never play this shot seem to think they have carte blanche when in a doubles match. I'd suggest only one in 4 end up as a winner, and statistically you're better off blasting one straight down your opponent's throat.
By the way - at my club night yesterday, I took on two "B" team players and was paired with a 60-something lady who was by far the weakest player on court. We were consistent, made few mistakes and crushed our opponents 6-2.
Finally, don't be disheartened if you feel you're not in the game, or letting your partner down. Keep apologies to a minimum and concentrate on getting your game on track. Next time it may be your partner who's not firing on all cylinders. It's about motivation and also letting your partner play their game. Understand each other's strengths and weaknesses and try to laugh, it's good for your tennis relationship.