Fire Emblem: Three Houses

• Fighting low level battles for study sessions does not consume a charge, only the ones that explicitly say that they consume will do so. Coupling that with the fact that units heal between battles, and you can access the market, you basically can farm levels until your units or gold run dry.

• The above tip only works in normal mode. Every battle costs points in Hard (making leveling up your Professor lvl even more of a priority since it gives you more battle points)

• It's hard to truly prioritize Professor Level, but just Do Things and it should get higher pretty quickly. Finding little glowy blue spots around the map can give you the points, too, and after a month or two you can even raid your students' rooms for casual reading material, worth a couple hundred points each.

• If you have A rank support with a student you want to recruit, you will recruit them no questions asked. Otherwise you'll need investment in whatever they admire.

• The skills with three stars are a unit's hidden talent, and are learned through direct instruction only - once unlocked it turns that skill into a strength, and grants a bonus ability or combat art. Either Byleth needs to directly instruct the student twelve times in that skill, or a faculty needs to directly instruct Byleth six times to get their Faith hidden talent. It's not a bad plan to unlock all the hidden talents you can just to give options to that character, whether you end up using them or not.

• Free days should generally be spent on either Exploration or Battles. Seminars can be worth it early on when you don't have many activity points, but later on you can more experience/motivation from just exploring and doing meals/faculty instruction directly. Rest is never worth it.

• Gardening and fishing should be done every time you explore - they don't take up a time unit, give Professor points, and Gardening can give "free" stat ups items if you manage to get the expected yield up to at least 3 (I have found no easy way to predict how compatible different seeds are, unfortunately).

• Choir practice is support points, Professor points, Faith experience for everyone in the group that's recruited, and Authority experience for Byleth. It's probably the best use of your first activity point in every exploration.

• Generally maps only have 10-11 deployment slots, with a bonus 1-3 slots for adjutants once your Professor level is high enough, and a lot of the professors/church members will become potential recruits as the year goes on. You absolutely do not have to recruit every student, just focus on the few people you think you'd actually deploy.

• When you unlock the ability to request mission assistance from people outside your house, request someone you're interested in poaching and attach them as an adjutant to Byleth. They'll gain support points with every action taken, making it a good way to get them to the recruited stage.

• Recruitment is based on the total of a skill, a stat, and Byleth's support points with the student (not support rank). If you get a message that they're "rather interested" when you try to recruit them, they'll probably join after a few gifts even if their rank doesn't increase. The general rule of thumb for recruitment seems to be 15 in the stat, C in the skill, and roughly C support rank, or alternately A support should be enough points on it's own should you go that route.

• Sylvain is a free recruit for female Byleths, and can be grabbed as soon as exploration unlocks.

• Relatedly, spoiler for the early game chapter related to Sylvain:
  the choice to return the Crest Weapon is not a but thou must, you absolutely can refuse to return it and have Sylvain start carrying it immediately.

• For Black Eagles specifically: it is a good idea to prioritize getting Byleth/Edelgard's support to C+ once that unlocks (after Chapter 4, I believe). They'll in all likelihood already be close based on normal gameplay, just consider giving them a direct push.