Blackjack is a game that lends itself to a system.  Here are some of the techniques, according to experts.

When the dealer's upcard in blackjack is:
     
     A two, three or four: Hit with 12 or less.  Stand with 13 or more.
     Five or Six: Hit with 11 or less.  Stand with 12 or more.
     An ace or 10: Hit on 15 or less.  Stand on 16 or more.

Caution: These are best odds only.  There are no winning odds.  Also, the odds assume a full deck.  They change as cards are played.  They should be used only when the deck is fresh or when you haven't kept track of cards played.  

Proper splitting of pairs (to make two hands out of initial two cards) can pare the houses blackjack advantage from 5.9% to 5.4%.  Here are some useful rules:

     Split two's and threes when the card the dealer is 
     showing is a two, three, four, five,six, or seven. 
     Never split fours, fives, or sixes.  
     Split sevens when the dealer's upcard is five, six or seven.
     Always split eights unless the dealer's upcard is nine, ten, or an ace.
     Always split nines unless the dealer's upcard is a ten or an ace.
     Always spit aces, even when casino rules permit
     you to draw only one card to each split ace.
     Never split tens.  
    
     Exception:
     If casino rules require that both of the dealer's cards at the blackjack table
     be dealt face up, split tens when  the dealer's count is 19.  
     Under most conditions, this turns a house advantage of 5.9% 
     into a player advantage of 1.71%.

Caution These rules are also based on a full deck of 52 cards.  Odds change as the deck is played.

I hope you have found these tips helpful, and don't hesitate to leave comments and your own tips!!!  Good luck, and I hope you win.