>>38374894"Let's go together" is the standard strategy that keeps allies close but expects you to move in a way to lead your teammates to get close to enemies as well. Positioning is important, so when in rooms, move in a way to get your partner next to an enemy with you so you can both attack. There are some strategies to give your AI partner a theme like, "Avoid the first hit" and "Go after enemies" if you want them to be more aggressive.
Raising IQ by feeding your partner gummis can unlock other behavior traits such as "Status Checker" which means they won't use the same status move if an enemy is already afflicted (ie the move Imprison that Vulpix gets immobilizes an enemy briefly leaving them vulnerable and having the IQ move Status Checker active means she won't use Imprison on the same enemy again until its free to move again). "Nontraitor" is another good one since being confused means you or your partners won't accidentally attack each other and just whiff attacks. There are several pools of IQ skills and each Pokemon learns from a specific pool.
Revival Seeds are very important to have since you never know when shit can go horribly wrong, as are Oran berries for health recovery. Many moves have different properties in the PMD setting (like Imprison before) so make sure to carefully read each move. Some moves like Quick Attack (also one Vulpix learns) are helpful in hallwalls since it can hit an opponent two steps away. You can also deactivate/reactivate moves you don't want your partner to use at any time or link them at Electivire's shop for a combo effect where they use each linked move in one turn (the drawback being the chance of wasting PP) but max elixers are fairly common so its not too big of a deal and you have your basic attack.
There's no rush in the story so feel free to take odd jobs or bounties if you need to collect rewards for later. It's possible to have three or four jobs in one spot that can all be done in one trip.