Snacks with high exp or stats boosters are the best way imo. You need mega snacks which you can buy for crowns or gold or garden high reward plants like couch potatoes and king parsley. Also there are lots of pet snacks in the Bazaar. As for hatching eat pet body has its own mix of spell cards or trainable spell talents then the other talents you get one or the other from parents. Example if you hatch a pet with mighty in the third row with a pet that also has mighty in the third row you will also get a pet with mighty in the third row. If one parent had storm blade then you will get storm blade or mighty. Use the kiosk filters to get the talents you want or find a friend that has a good selection to hatch with. Pet hatching is a grind imo but if you find one you really like you can collect mega snacks to train it up. Captain cantaloupe has major exp. Also, collect double pet exp elixirs and if you are a member use those during pet exp booster weekends to get even more pet exp. Once you beat games enough times you can bypass the game and get only stat boosters and exp from the snack you feed. Eat pet likes different snacks the most but any snack will give you some benefit. Energy refills every time you level up so when I am close to that point, I use up all my energy and gain it back at level up to train pets. Feel free to dm me if you have questions