It does not matter if you win or lose, you will still be rewarded with a card. Keep playing to fill your card books and train. Have boost cards that can increase all the skills available to get an advantage during matches. Because you can only use one boost per fight, make sure it is used at the best moment. When you get two cards of the same type, combine them to get extra skills on your basic card. Afterwards, begin training your cards. At first, train your medium ranked cards in order to increase your chances of winning. As you progress to better and rarer cards, begin using the rare cards to level up the existing cards. Always combine cards of similar levels or you may lose points when combining superstars. Try getting your cards to at least level 7 before combining then. Instead of maxing out one character at a time, go with all of them at once and try to keep them to as high of a level as possible. Start with your best superstars because you will probably use them longer, followed by less useful cards in order of strength.