My personal preferences vary for my betting type. For cards, a casino setting is preferred. I also enjoy online betting for offline events, like on hockey and such. It seems to be easier to win money at sports betting if you can read the numbers properly. Also, knowing the teams helps too.
I only play hold'em mostly at casinos, sometime blackjack. I've only gone a few times, and have only lost once, but am still up more than $1200 on cards. I just keep playing that "know when to hold'em, know when to fold'em" song while I play. Keep a cool head too, and know the rules, feel the cards, watch how many are in play... There are so many tips, but ultimately it boils down to luck. Summon that shit like it's your pet goat.