1. Attack first. Most attackers want to attack first.
2. Push well. This means low, deep, heavy or varied, quick off the bounce, and to wide angles, with last-second changes of direction.
3. Go to his strong side first, when you get to choose the shot. If his strong side is the forehand, then go there, and then come back to the backhand, forcing the forehand attacker to move and play backhand.
4. Serve short to his strong side, bringing him over the table, then go deep and wide to the other side.
5. Fast, breaking serves to the weak side. If he has a big forehand, serve deep and very wide to the backhand so the ball breaks away even wider - making it very difficult for him to play forehand. (If he does, develop a fast down-the-line serve with the same motion, and ace him when he moves too soon.) If he's stronger on the backhand, set up on your forehand side and do a deep sidespin serve to his wide forehand (such as a tomahawk serve), so it breaks even wider.

To improve, it's important to do footwork drills. Some are simple, such as side-to-side forehand-forehand drills. Others are more complicated. For example, you might do a drill that starts with your partner pushing to your backhand, you backhand (or forehand) loop to his backhand, and then he blocks to your forehand.

Advanced players understand that in these rote drills, they are practicing only the footwork and the stroke. But many beginning and intermediate players don't get that, and try to play it like it was a match. After that first opening shot, they know the next ball is going to the wide forehand - but because they would not know this in a match, they wait until the opponent does the shot, and then move. That would be fine in a random drill, where you don't know where your partner is hitting the ball, but not in the rote drill described here. And so what happens is you end up knowing where the next balls going - to the forehand - but do not immediately move there. Result? You are practicing hesitation!

So remember that if you are doing a rote drill, don't hesitate to move immediately to where the next ball is going - you are practicing footwork and strokes, and don't want to make hesitating a habit. When you want to practice reacting to where your partner is hitting to, do a random drill for that, where you don't know where he's going, and so have to truly react.

A common mistake I've seen is for a player to find something that seems to work in a match, and then go to the well too often - they use that tactic so often that the opponent gets used to it. This is a double-whammy - if you do this, not only have you turned an opponent's weakness into a strength, but you have to almost start from scratch in figuring out how to tactically beat this player.

This is why it's important to find more than one way to beat an opponent. There might be one primary tactic, but you need secondary ones as well. Try to match your strengths to the opponent’s weaknesses. Or match your strengths against their "average" shots, or your "average" shots against their weaknesses. But you do want to find the best tactic that works, and use it as often as you can get away with it.

With experience, players develop the instinct on how often they can get away with a tactic that works. They also learn the difference between something the opponent simply can't do effectively, and something the opponent will learn to do effectively if given enough chances.

Sometimes it's a good tactic to go after an opponent's strength. After all, his game is probably based on getting that shot into play, and so you are probably going to have to face it - so rather than have the opponent choose when he'll use it, why don't you pick choose those times?

For example, suppose your opponent has a very nice forehand loop. He's going to use the shot; there's no stopping that. You could play into his backhand, but then he could step around to use the forehand, and he gets to choose which shot he wants to do it off of. So why not simply attack his forehand side yourself, and force him to use his strength off a difficult ball, and then come right back to his backhand side, where he now has to play his weaker shot while moving?

Or suppose your opponent is a very good blocker. You keep getting stuck in rallies where he's quick-blocking the ball around the table, rushing you and forcing you into mistakes. Since he's going to block anyway, why not throw a slow, deep, spinny loop at him? That's often the most difficult ball for a blocker to quick-block - he has no speed to play off, it's deep so he can't really rush you, and the spin makes it tricky to block. And so rather than getting quick-blocked all over the table by his blocking strength, you'll get a weaker block that you can really attack. You've turned your opponent's strength into a weakness.

If a player has a good loop against deep serves to the backhand - whether forehand or backhand - you might be able to turn this into a weakness. If you serve very short to his forehand, he might have to stay closer to the table when receiving then he'd like - and now he gets jammed when you do give him that deep serve to the backhand.

Similarly, you can find ways to negate an opponent's strength and turn it into a weakness. When you do so, it's a double-whammy - you've both taken away his strength AND found a weakness!

Here is how I would describe the "grinding" mentality. It means a willingness to play as many shots as needed, never missing, while refusing to make a single weak return, whether pushing, chopping, or counter-hitting, with a focus on returning anything that's not smashed or loop-killed, and relying on your reflexes to return some of those. It's primarily a defensive mindset, though grinders will often attack when given the chance. Some counter-hitters can play with this mindset and be pretty aggressive. Some fisher-lobbers styles play this way as well, with the underlying assumption that, to them, when fishing and lobbing they aren't making weak returns, since they are confident they can return the opponent's smashes as long as they keep their balls deep on the table.

How do you play against such a style? The keys are patience and decisiveness. If you play a grinder the same way you'd play an attacker, then you'll likely make too many mistakes, which means you are playing right into their game. Instead, you should take your time on your shots and focus on consistency until you get the right shot. After all, unlike when playing an attacker, you aren't fighting for the attack. But when the shot's there, you have to instantly change your mentality and end the point decisively. The difficulty in playing this style is finding that balance between consistency and decisiveness. 

There are two great ways to learn to play against this type of mindset. The first is obvious - play against this type of player until you are comfortable. The other is to experiment with playing that way yourself, so you can see it from their point of view, and see how vulnerable they actually are, since they are basically letting the opponent dictate much of the play. Not only will you learn to play against that type of style, it'll improve your own consistency and ability to avoid weak returns, which will likely help your own game. So . . . happy grinding!