Talk to Everyone
You might be a (somewhat) silent protagonist, but that doesn't mean you shouldn't talk to people. Social links with your Confidants are the crux of the Persona franchise, so get to know people!
More so than just that, listen and talk to strangers out in Tokyo. You can learn a lot about the world around you, things that will happen in the future, and more, just by being observant and patient.
Collect Every Persona
Gotta catch 'em all, right? As you play through the game, you'll come across tons of Shadows that call be captured to become your Personas. Even if it means getting rid of one you're currently holding, try to capture every new Persona you can. This will help a ton with late-game fusions and for your second (or later) play through.
However, all Personas you capture have the same base stats and abilities, so you don't need to catch repeats in most cases.
To Kill or Not to Kill?
During your dungeon crawling in Palaces and Mementos, you'll sometimes come across Jewel Demons. These Shadows give a good chunk of EXP and a ton of yen when defeated, but they're also invaluable for Strengthening your Personas, stating around the mid-point of the game. Make it a priority to catch these demons, but once you have one, feel free to take down the same versions to reap the rewards since you can always get them from your Compendium in the Velvet Room. It's a great way to level up quickly early on in the game.
Be Socially Sophisticated
You'll find out early on that not everyone is interested in getting to know you right away if you don't pique their interest. Increasing your social stats, such as Charm and Knowledge, is important for these sorts of people. However, it's especially important for unlocking the Death Confidant's ranks to get healing supplies, the Hanged Confidant to upgrade your weapons, and the Temperance Confidant to lift the burden of daily chores off your shoulders. Don't leave these to the last minute or you'll miss out on some great perks when you need them most.
Be a Yes Man
If someone texts you at night or during the day to hang out, even if it won't give you a rank up with their Confidant rank, consider saying yes. You'll often get a boost to your social stats, reputation with the inviter as well as someone else who might meet up with you, unique items, and more. Early on in the game, you're almost definitely going to be invited to a location you've never been to. Hangout Spots are great for maintaining progress with your Confidants when you aren't close enough to rank up yet, so be sure to unlock them through other people.
