Persona 3 - Making the most out of each day
A huge part of Persona 3 is making the most out of every single day. You should never let a day, an evening, or an afternoon go to waste. Even if you're tired or sick believe it or not there are still some things you can do to not totally waste the day. Typically every day in Persona 3 consists of waking up and going to school. You usually get control of your character after his day in school ends. You can perform 1 activity before evening at which point you're sent back to the dorm and it switches to evening.
Once Evening hits you can go take Koromaru for a walk once you have him or go back to the mall to do karaoke or drink coffee. You can also raise Social Links that are available during the evening hours, if you have any to do. After you finish the evening activity your character will automatically return to the dorm with your final two options being study before bed or sleep. If you're sick or tired never study before bed, you'll just waste time and you won't get good sleep.
If you are sick or tired right after school you should go down to the first floor and over to the Nurse's Office. Speak with the Doctor and he will ask you to drink a potion, it never makes you feel better but it raises your Courage a little.
Now, depending on what you're looking to raise in Persona 3 will determine how you want to spend your days. For the first half of the game you're primarily going to want to raise your Academics, Courage and Charm. Academics is definitely the hardest to raise out of all three of them so prepare to give that more focus than the other two. Charm and Courage are actually both relatively easy to max out.
Courage one of the easiest ways to boost this is to watch scary movies or sing karaoke. The movies you see are random and can raise any of the three stats + it costs more money (1500 a ticket). You can see them at the Port Island Station. For Karaoke you'll be taking part in that at the Paulownia Mall. It's only 800 yen. They are also closed on Saturdays usually from being overcrowded.
Charm you raise quite quickly if you provide the teacher with right answers in class. Also you can raise your charm by drinking coffee at the mall for only 500 yen.
Academics as aforementioned this is the hardest of the three to raise. You can raise Academics through answering questions right in class as well as studying each night, unless you're tired of course. After class each day you can visit the Library on the first floor of the school to raise your Academics. You can also enter the Faculty Office and get a lecture to raise your academics too (which doesn't pass time). Also, another way to raise it is by visiting the Naganaki Shrine each day after school and dropping in a 100 yen donation. If your character is feeling "Great" the bonus to your Academics will be more than normal.
That's all for the three major stats in the game. You may find other ways to max each one than the few ideas I listed. There are also numerous events throughout the game that will give you an opportunity to raise each one, like the classroom situations where you have to answer a question occasionally.
After your stats are maxed out you can hit up the Arcade in the Paulownia Mall if you have Persona 3 FES. This will allow you to raise your Persona's attributes such as Strength, Magic, Luck, things like that. Each Arcade game is about 2000 yen so this isn't something you'll want to be indulging yourself in early on in the game.