Don't let the number of monsters on the field mislead you. There are far more enemies that meets the eye. If youíre fighting a high-level enemy, he will probably have even more monsters ready to take place of the fallen ones.
Use your training sessions to improve your fighting skills. Whenever you use a combo move during training you get a power boost.
Monsters do not get mightier in time. For that reason, it might be wise to get rid of those weak, small monsters that you used in first levels. Although they are veteran fighters, they really only take up space. Recruit a more powerful creature instead.
You should always try to make use of the rare creatures (if you can find them, that is).
Learn when to use primary and when to use secondary skills. The latter ones can be quite useful if used at the right moment.
You need a range of different elements in your basic team. This way you can match your opponentís forces more easily.
There are many websites online that offer a hack which lets you have all the in-game content for free if you only visit a specific link. Donít fall for it, as the link probably leads to malicious website.