Reusable TMs and League team building
Use Generation V mechanics to build a flexible party for the original Unova League.
Original Black and White; their sequels have different routes and encounter availability.
Use TMs without hoarding them
Generation V makes TMs reusable. Once you own a useful TM, you can teach compatible party members without consuming it. This makes it easier to revise coverage for the next Gym. HM removal still has its own rules; reusable TMs do not make every field move freely replaceable.
Build coverage around actual move stats
Compare physical moves with Attack and special moves with Special Attack. A strong Pokémon can perform poorly with the wrong category of move. Keep at least one reliable same-type attack while adding coverage that solves a specific weakness in your party.
Understand the four League themes
Shauntal uses Ghost, Grimsley Dark, Caitlin Psychic and Marshal Fighting. Dark coverage helps against two themes, but a Dark-heavy party creates trouble against Marshal. Choose the order based on your prepared team rather than assuming the first doorway represents the easiest opponent.
Check abilities before switching
Levitate, immunities and other abilities can overturn a simple type-chart plan. Read battle messages when an attack has no effect. If a counter fails, identify whether the problem was typing, ability, speed or a secondary effect before changing the entire team.
Keep recovery distributed
Give more than one member a useful role when your main attacker is unavailable. Carry status cures and PP restoration for long sequences, and save before major challenges. Do not plan around Fairy attacks or later-generation evolution methods: they are outside these original DS games.
Check the edition note above before following a route. Suggested preparation and tactics are editorial recommendations; alternative teams and routes can also work.