Remember that your opponent needs a certain number of points for the initial meld (either 50, 90 or 120). I use the rule that in general they are unlikely to have 50 before turn 2, unlikely to have 90 before turn 5, and unlikely to have 120 before turn 7 (sooner if wild cards are allowed in the opening meld). Therefore you can take less care over what you discard in the early stages of the game. It can be useful to discard high singletons early on. Hold your Black 3s and 2s for later in the hand when there is a risk of your opponent picking up.
Don't freeze the pile if neither of you have melded yet. There is no point - it simply stalls for one turn. Next time round your opponent might pick up, and you've lost your valuable wild card!
Don't be lured into feeding wild cards into a frozen discard pile. You are only putting off the turn where you will have to play a card which your opponent can pick up, and your wild cards are too valuable to lose, and can hand your opponent the game when he picks up. Think hard before being sucked into feeding wilds turn after turn. Do you really want what's in the discard pile, or is it just a few melds of low cards?
Hold onto your 2s as long as possible. However, they will hurt if you are stuck with them in your hand and your opponent melds out. If you have both 2s and jokers, meld the jokers first as they are worth 50 points rather than 20 - painful if you have a handful of them when your opponent goes out! Use them if you are close to melding out, or if your opponent has any Canastas - otherwise they may be more use later on to meld a pair, and a "natural" Canasta (with no wilds) is worth many more points and worth waiting for if possible.
You can safely throw anything your opponent has already turned into a Canasta (though it can be useful to hold one back until you really need it) - they can't meld with these even if the discard pile isn't lfrozen.
Be “Mindreader” – develop ESP
Throwing a 2 says "I want this discard pile". Beware of the messages you are giving your opponent - they may guess what you are holding, and will probably try to block you.
Throwing a 3 says "I don't want you to take this discard pile". If there's a good meld in there (whether on its own or it fits with your opponent's existing melds) that's ok - if not, you've probably used your 3 too early.
Making a Canasta or two shows you are thinking of going out and may lure your opponent into melding (whether you intend him to or not).
The "follow me" trick - Everyone uses this at some point! The idea is to persuade your opponent to throw something you can pick up on, especially if the pack is locked.
Decide what you can afford to throw away (leaving yourself at least a pair of that card, and enough points to meld if necessary). Be prepared to lose the card.
Make sure you don't choose a card that your opponent knows you have others of - for example if they were in the discard pile last time you picked up. He's unlikely to have forgotten!
Ideally there will already be one or two of this kind of card in the discard pile, so it looks more natural when you discard another one. This also reduces the odds of your opponent having enough of this card to pick up the pile himself.
You can also be canny if you notice your opponent throwing away the same card time after time - if you get any, don't join in (he may also be trying this trick) but hold them so you can pick up in future.
Hopefully your opponent will be lured into playing the same card as you discarded - whereupon you pick up!
If your opponent constantly "has no discard" (i.e. has only one card in his hand, but not enough Canastas to go out) then simply throw yourself a card which you can pick up on next time round.
Different types of player and strategy
There are many different strategies but surprisingly, many players tend to stick to one method. Good players will use all of these strategies as needed, rather than being restricted to one style of play. Here are some ideas to counter those strategies:
The player who always freeze the pack
Don't get drawn into throwing your wilds away. Chances are that in a few turns you will run out of wilds, he will pick up - and use those wilds to meld out
Keep your blacks 3s back as late as possible
Count the cards in the discard pile carefully, and only throw cards that they are unlikely to have a pair of. Quite often there will be 6 or more of the same card in the discard pile
Try the "follow me" trick to get him to throw something you can pick up on
Meld as little as possible, until he lfreezess like he may win or there are only a few turns left before the draw pile runs out
The player who tries to go out on his opening meld
They often lock the pack and rarely pick up, but when they do they win the hand, so meld as little as possible
But do meld Canastas, and meld high cards like Aces and Jokers which will hurt if they are in your hand when your opponent melds out
Meld cards you hold 5 or 6 of - keep a pair in your hand and only meld the others until you have Canasta
Don't be afraid to make the first move - you may scare the opponent into melding before they are ready. Move when you are ready rather than when you feel pressured into it
Watch discards for odd patterns such as high cards or the same card twice in a row. The opponent may be trying to lose their singletons and odd pairs so they can meld out soon
The player who always melds where possible
This is the easiest player to defeat. Hold back your melds and then when they have melded three or four different cards, lock the pack
Don't feel pressurised into melding as much as possible too!
Do very little - you can usually see when they are close to going out and react at that point
Adapt your strategy to each player, and adjust it between hands so they can't work out your methodology. Keep one step ahead - if you are playing catchup and feel forced into melding, or feeding wilds into a locked pack, stop and rationalise, then change tactic if you need to. A flexible playing style is most effective

