If you find a tactic that really gives your opponent trouble, do some serious thinking about how often to use it. You may have two options: 1) use the tactic to win one game; or 2) use the tactic to win the match. If you want to squeeze an entire match out of the winning tactic, then you don't want to overuse it and allow the opponent to get used to it.

For example, suppose you have a serve your opponent misses over and over. Unless the opponent is brain dead, if you overuse this serve, he'll get used to it. He'll also expect the serve at key moments - so you have to decide whether it will still be effective at that time. If he hasn't made many good returns of it in the past, then he'll probably have trouble with it under pressure as well, so most often use it at these key, pressure-packed points. When he does make a good return of this serve, hold back on it for a while, and then surprise him with it again. 

If you only have one serve that gives the opponent trouble, perhaps you can turn this into two by doing some variation of the serve? A different spin, speed, or depth, or even serving from a different part of the table might be enough variation to allow you to use it more often.

Suppose an opponent with a big loop keeps missing when you push heavy to his backhand. Do you really want to warm up his attack against this by giving it to him over and over? I've had many coaching experiences where a player went to the well too often, and tactically had nothing left in the last game. I once coached a match where the opponent had a huge backhand loop off a deep push to his backhand to follow up his short backspin serves. In the first game, the opponent missed over and over. Between games I suggested using the tactic at the start of game two, then holding back on it a bit, perhaps pushing more to the forehand, pushing short, or flipping. Instead, the player I was coaching pushed long to the backhand over and over, took an early lead - and then suddenly the opponent's big backhand loop started hitting. Afraid to push deep to the backhand, my player started pushing to the forehand, where the opponent was even stronger. Afraid this late in the match to start flipping or pushing short, my player fell apart, and the rest of the match was a rout.

It's important to come up with several winning tactics, and vary them. Experiment early in the match, and find what works. If you have one serve that works, find a variation of it so you have two. If you have two serves that give an opponent trouble, go back and forth between them somewhat randomly, mixing in other serves as well, perhaps looking for a third effective variation. If you build up a lead, perhaps temporarily retire one of these serves for later. But be careful - don't blow a lead by failing to use what was a winning tactic. It's all about judgment. 

If you want to score more points against us, focus on consistency, placement, and steady attacks instead of wild swings. Stop hitting everything crosscourt, go after my playing elbow more, and change directions at the last second so we don't know where you're hitting the ball five minutes before you hit it. And for god's sake, develop some good serves, both long and short ones. While you're at it, work on your receive - it takes practice, but if you focus on control, you'll get that control. If you do all this, and can put the ball away when you get an easy shot, you'll start beating us and we'll teach you the secret handshake. That is all. 

When you make a series of shots and then miss one, remember the feel of the ones that hit, not the one that missed. It's the ones that hit that you want to ingrain. Think about the miss only if you do it over and over, and then only think analytically to figure out what the problem is, and as briefly as possible. Then forget about the misses and think about the feel of the good ones. 

The primary danger of attacking with the forehand from the backhand corner (usually with a loop) is that you are leaving the forehand side open. Yet, you don't have to be a speed demon to cover that shot, though that helps. Balance and technique are more important. Here are keys to how to play the forehand from the backhand side without getting caught on the wide forehand. (Note - the advantage of the forehand from the backhand side is that it's usually easier to generate power with the forehand.)

• Balance. Often a player is in such a rush to step around that they are off-balance when they finish the shot. Others simply follow through way off to the side. In both cases, by the time they have recovered their balance, it's too late. Imagine a pole through your head, and as much as possible rotate around that pole. This gives you great torque yet leaves balanced and in the same position as when you started the shot.
• Depth. If your shot lands short, it's easy for the opponent to block aggressively to your forehand. If you keep your shots deep, you have a lot more time.
• Placement. If you put the ball very wide to the opponent's backhand (for righties), they have no angle into your forehand. In general, go down the line only for winners, since you'll be wide open to an aggressive angled block to your forehand.
• Speed. The harder you loop, the less time you have to recover. Often it's a good idea to loop slow and deep from the backhand side, since the slowness and depth of your own shot gives you time to recover. Alternatively, loop kill so the ball rarely comes back, so you don't have to worry about the wide forehand as much. It's those medium-speed loops that are regularly blocked to the wide forehand for winners.
• Backhand loop. There's nothing like a backhand loop from the backhand side to keep you in position!

A fast, down-the-line serve from the backhand corner (normally done with a forehand pendulum service motion) is a valuable serve. It's great at catching righty forehand loopers off guard as they look to loop your serve from the backhand corner. It's also sometimes good against more neutral players, as they aren't used to fast serves to the forehand and so can be erratic against it. It's even effective against lefties, who are often guarding against serves wide to their forehand, and so are vulnerable to this sudden serve to their wide backhand. Against lefties, however, you'd look to ace them by going crosscourt to their forehands, though you are less likely to get an ace as players generally guard the crosscourt angle. (Lefty servers, this serve is effective for you as well - but I'll let you work out the specifics.) So develop this serve or you will be handicapping yourself against some players.

If you aren't sure how to do the serve, ask a coach or top player to demonstrate. But the key is to fake as if you are serving crosscourt, then at the last second change directions and serve fast topspin down the line. Contact point should be a bit behind the table so that the first bounce can be near your own end-line, which gives the serve the maximum amount of table to drop and hit the other side. (This is true for fast crosscourt serves as well.)

Pick and choose when to use this serve. Often you can tell by the receiver's stance and body language if he's looking to step around. Even if he's not stepping around, if a receiver looks a bit flat-footed, he's probably vulnerable to this serve.

Once you can do the serve effectively, it's time to make it even more effective. Here are two ways you can do that. First, you can use spin, either sidespin either way or extra topspin. If you do, make sure to put more power into the serve so that you don't sacrifice much speed for spin. Extra topspin pulls the ball down and allows you to serve even faster.

Second, contact the ball with the racket still aimed at the righty receiver's backhand, but hit it down the line with sort of a slapping sidespin (your racket going from right to left at contact). This is my favorite. Typically the first time I go down the line, I do it the "easy" way, changing the racket direction at the last second. Now they are watching for that last second racket change, so I don't give it to them. By keeping the racket aimed to their backhand, you catch them moving to cover that shot, and their forehand side is open.

Once you've done a fast down-the-line serve, the rest of the match the opponent is guarding against it, and guess what? All your other serves become a bit more effective.