Take a card on 16 or lower because you can't win unless the dealer bust.
But stand anyway if the dealer shows a 4,5, or 6 because he his more likely to bust.
'Doubling down' involves doubling your wager and getting one more card when you feel strongly that you will beat the dealer when doing so.
Always split 8's or 7's against a dealer's card of equal or lower value.
Always split 2's or 3's against a 4, 5, or 6.
Always split aces.
Never split face cards, 10's, or 5's.
Use basic Black Jack strategy. Most Black Jack players will lose about 2% of every bet because of improper play. In casino black Jack be sure to have a good idea of what basic strategy suggests, and don't be afraid to ask the dealer for help if it’s an unusual situation. For online black Jack consult a website or book to help you make your decision.
To slow down your playing time choose a crowded table where you will be able to play fewer hands. Being the sole player at a blackjack table is not as fun without the interaction. Furthermore, your bets can be placed very quickly and you can run through your bankroll in a flash.
Always wear a watch, preferably one that beeps on the hour. For online Black Jack you should go so far as to make sure there is a clock in your field of vision for your entire playing time. At casino Black Jack the only way to ever get the time is to bring your own pocket or wristwatch. Whether online or not, always pay attention to how long you've been playing for, and limit it to a reasonable amount of time.
Increase the amount of your bet only when you're winning. It is natural human instinct to do the opposite and increase your bet when you're losing, to try and make up losses. You should truly only increase the amount of your bet if you have a good situation presented, not simply a run of wins, but it's a less risky action to perform if you're not already on a losing streak.
Be aware that some casino Black Jack tables use the 'Dealer hits soft 17' rule which increases the house advantage. Look for tables where dealers must stand on all 17’s.
The casino's Black Jack dealer will bust more often when his up card is a 2 through 6 and he will complete more hands when his up card is 7 through ace. Basic strategy usually suggests standing when the house is showing a 6, even if your hand is a 13. Since this seems almost counterintuitive, and human nature is to want to yell hit me on a 13, it is a most common downfall for novice Black Jack players. Either consult basic strategy, or let 'dealer busting cards' become the source of a new instinct to stand and not hit.
To determine an appropriate bankroll amount for a table session of Black Jack multiply your normal bet by 40. This will allow you to play for a reasonable amount of time, and once that time has gone by, you can make your finishing moves and head out. It also usually represents a long enough length of time to determine a 'point' worth knowing for card counters.
In Black jack it is always to your advantage to play against as few decks as possible. You can always ask around at the casinos and find out how many decks are in use. Also pay close attention to their shuffling rules, how often they shuffle, how deep into the deck they go before reshuffling, the deeper the better for card counters.