Mahra: Careful planning, specific goals, careful with positive encouragement.

Phillip: "You don't need defense if you're too fast to hit"

Sivrit: Traditionalist warrior approach, fight the strongest opponents he can find.

Fausto's trains his Pokémon to use their own natural instincts during battles while also periodically giving commands when he deems it necessary. Plays into his 'whole wanting to be free but also scared of losing any control of a situation' thing

If Odd's team ever is in the mood to train, he more often than not asks the Pokemon in question what exactly they'd like to focus on for the session (be it the applications of a move, strategies against a certain opponent, traits related to their stats, etc.), And focus on that while trying to weave in some general upkeep of their skills during the specified training

The vibe is usually very casual, though: Odd is by no means a professional battler, and given some of the life-threatening strife they've been through in the past he wants his team to take training only when they want and at their own pace.

Eve often takes morning runs with her Pokémon, but if she's struggling with a specific opponent she'll adapt their training to fit whatever she thinks they need to pull through!
Sometimes means sparring amongst the team, or setting up some sort of "training course".

Ryoko, my other most battle focused OC however, wrestles with her dragons to train their strength and her own. She doesn't usually bother with smart strategies, and only believes in landing hits and landing them as hard as possible.

By fighting with them

Avian: Regular exercise and wellness checks. Avian will literally host meetings with his team even on zoom if he has to, sit them around a table to discuss strategy and collaborative action then follow it with an hour of training sessions and sparring if need be.

Stahl: Has others do it for him.

Arryn: Travel and exploration paired, sparing with each other and getting into fist fights with legendaries.

Ming-Ming exercises with them! Whether light jogging or stretching, she's often on the move with one of her partners or three. She's a perky lass and a lot of her Pokemon tend to be on the energetic side, so it ends up working out!

Jin takes the approach of teaching her mon their strengths and weaknesses, this includes type advantages as well as strategies for fighting given their respective body shapes. It's basically a strategy similar to how a martial arts teacher would teach their students. And to go even further, Jin doesn't give commands during battles instead trusting her team to make decisions for themselves.

The normal method, he usually gets them to spar with one another to both see their strengths and weaknesses in battle.
Another form of training is traveling to Galar and beating down plenty of Dynamax Pokemon, he also fights Terastylize Mons in Paldean
The last known, and his best method is him fighting other Trainers, Gym Leaders, or Evil Team members, he loves thrashing a strong evil team member