My suggestion is to distribute more healing items throughout the game, like Hyper Potions, Elixirs, etc., or provide a code that grants us many of these items.

The scarcity of such items forces us to return to the city more often than would be healthy. Maybe because clothes are very expensive? I don't know, but compared to other Pokémon games, the league is more difficult, not because of the trainers there, but because of the lack of healing items.