Ever dice would not be in my option because we may see the lose more than winnings in dice gambling. I would like to do betting or poker room games to use the strategy and gathered information to use and win continuously but we cannot do that in dice game. If you avoid dice even you will also consider gambling is one type profitable earning method in btc.
Martingale again, he will need to play and lose more of his money before he figure it out. After so many threads about it, and so many stories about lost money with martingale strategy some people still think that they can make money using it.
Winning and losing are part of the any game, you need to count your loses and expect good wining hand after. I like to play poker more then other games, in poker you play against other people and its more interesting then other games. You need to follow other players and their cards, your cards, you can win with bluff, or you can be strong and others to fold, you need to know how to take more money with luring other players to pay, books are written about poker and how to play it.