1: Basically the easiest, if you lose a battle reset the game and fight again until you win so you will have no losses.
2: If your near a treasure chest save the game then open it, if you don't get an item you want, reset and try again (items are randomly picked).
3: If your in a dugeon and just entered a new floor, save it, then use Sis Lens and look on your map and find the stairs and memorize a path to take to get there, then reset the game and go to the stairs without using Sis Lens.
4: If you don't have Sis Lens, save the game next to a set of stairs, then go to the next floor and look around for the stairs until some one fights you then start over and go down the stairs, sometimes it will put you next to a staircase.
5: If you have a Derived monster and want to use it, put each monster of its type in so you could have more of the same cards and use them more. For example, if you have Rock Dino dino/golem, then put Rock Dino, Dino, and Golem on your team.
These are some helpful tips, I really like 2 and 3. Adios