1. Using Rare Candies: Rare Candies are a valuable item that can be used to instantly raise a Pokemon's level by one. They can be obtained as rewards for completing certain tasks, such as defeating powerful trainers or completing quests, or they can be purchased from shops.
2. EXP Share or Exp. All: The EXP Share or Exp. All is an item that allows a Pokemon in the party to gain experience points even if it doesn't participate in battle. This is a great way to level up weaker Pokemon or those that you want to save for later use.
3. Grinding: This involves battling wild Pokemon or trainers over and over again to earn experience points. Grinding can be time-consuming, but it's a surefire way to level up your Pokemon quickly.
4. Lucky Eggs: Lucky Eggs are a consumable item that doubles the amount of experience points earned from battles for a limited time. Using a Lucky Egg can help you level up your Pokemon twice as fast as usual.
5. Chain Battles: In some Pokemon games, chaining battles can yield increased experience points. This involves defeating wild Pokemon in succession without being defeated or allowing them to escape. The more Pokemon you chain, the more experience points you'll earn.
6. Pokemon Day Care: Leaving Pokemon in the Day Care can be a great way to level them up passively. While they are in the Day Care, Pokemon will earn experience points based on the number of steps taken by the player.
It's worth noting that some Pokemon may have different methods of leveling up or evolving. For example, some Pokemon may require certain items to evolve, while others may level up through friendship or trade. Be sure to check the specifics for each Pokemon if you're unsure how to level it up.