Last month, I restarted a HeartGold save file. My challenge was not to evolve my Pokémon until they learned the moves I wanted them to; also, battles had to be on set mode, not shift mode. Additionally, I was using an all-female team.
More recently, I battled the Elite Four and Champion. My team was Croconaw, Flaaffy, Growlithe, Espeon, and Nidoqueen, with the sixth-slot taken by an HM-slave. I had them leveled to fifty, but I couldn't beat Karen, so I then leveled them to fifty-five and evolved Growlithe into Arcanine. Finally, I could beat Karen and the other Elite Four members with ease, but Lance was another story. He had two or three Pokémon left, while four of mine were fainted; the two non-fainted ones were Croconaw, whose HP was in the red, and Arcanine, who was completely healthy. Believe it or not, Arcanine defeated at least one Dragonite and Lance's Charizard; although her HP was low by the time of our victory.
Shortly thereafter, I traveled to Kanto. I allowed my Flaaffy to evolve into Ampharos, but I kept Croconaw at her regular state until I defeated Blue. I slightly loitered in Kanto, as I wanted to register Blue's number and have him call me before I even met him. (It works, by the way.) Currently, I am training on Mt. Silver so I may challenge Red.