Mine has tended to be ALWAYS play with all cash and NO BONUSES!!
If im trying for something big then I always try and make sure I have potential a relatively high deposit amount.
I start off by depositing maybe $50. then play blackjack. If I lose 10 hands in a row or something like that then I know full well the casino is playing tight, thus its not going to be my day so I come back later.
If things seem to be going ok on blackjack I try to get a nice balance to play with (so if I start with $50 I try to get it to $120). Then I get on the slots.
My method with slots is to bet quite low to start with (possible 40c or 60c a spin), then if I lose $20 or so of my balance I start betting higher (usually $1+ a spin) and hope I hit a bonus round of something big. If I hit something nice I lower my stakes again and continue playing or change slot.
If I end up continually losing however I go back to blackjack, try to put my balance up again and of course repeat the process.
Some sessions I play like for hours and have a big lot of winnings but then the slot tightens up and when I go to blackjack it eats my remaining balance, however a few of the times I have been lucky with this method.
Recent withdraws with my method:
MG casino - $3800 (Made about 15 deposits of $50 each time to get that much, the last deposit was a frenzy, played BJ, bet something like $40 1st hand, then $75 second, then played 8 or 9 more hands at $125 a hand, the luck went my way and I won all of those hands whilst getting BJ a few times, which put my bankroll back up to over $1000, then hit some nice wins on slots at $1+ spins, followed by a load more winning hands on BJ to finish the balance

. Technically the $3800 came from a $50 deposit)
MG casino - $7900 (Again made a few deposits, 6 in total I believe, each totalling $80 a deposit. Once again my last deposit of $80 was what got my balance that high. Frenzied high bets on BJ made the 1st $3000, then even higher than usual bets on slots of $2+ got me a further few wins combined to $2500, finally some more luck on BJ and a final $700 free spin hit on "reel baron" gave the final balance)
In all fairness it doesnt always work for me like that. Blackjack can be my best friend by then easily switch to my worst enemy. Those times it did my balance well and won most of my cash but all too often it has the reverse effect where slots put me up nicely and BJ takes it away
