Final Fantasy I

Party Composition

• If there's a single thing you take away from these tips, make it this: Bring a Fighter. The rest of your party make-up is mostly up to you, but most of the good armor is Fighter-exclusive for the first 2/3s of the game, and without a tank in the first slot, you're going to get massacred if you don't know exactly what you're doing.

• Thieves are the Magikarps of Final Fantasy 1, extremely mediocre right up until the class change 2/3s through the game, at which point they become Ninjas, who are amazing.

• If you're using a Black Belt/Monk, take their weapon and strip them completely naked once they hit level 8. They'll be more effective offensively and defensively this way right up until the benefits of endgame armor/accessories outweighs the slight defense loss. (This is also, not coincidentally, the point at which they upgrade from 'pretty okay attackers' to 'direct damage gods'.)

• Red Mages are expensive to maintain, and will never be the best at anything (especially late game), but they're decent pinch hitters, and a good place to dump weird utility spells you don't want to clog your main caster(s)'s spell lists with.

• Black Mages are the kings of burst damage and have some excellent buff spells, but are frail and physically weak. Great for nuking bosses and problem encounters, though.

• White Mages are probably best used for crisis healing and defensive buffs; leave the post-combat patching up to your Potions. This goes doubly true for PURE/Purify and SOFT/Stona, skip those two spells entirely and just use the items.

General

• Save early, safe often. There's nothing worse than losing hours of progress because you got blindsided by a tough encounter you didn't expect. (Tents, etc. are great for this.)

• Your first priority is grinding to Level 2 outside of the starting town. This will likely double your characters' max HP, and make the trek north much simpler and safer.

• Once you can afford to, stock up on Potions and Antidotes. Being poisoned far away from town without any antidotes is a death sentence, and a stock of potions will increase your longevity by leaps and bounds.

• The strongest enemy in FF1 is attrition. Make sure to pace yourself so you'll be able to survive a trip back to town from the dungeon, especially if someone keels over unexpectedly.

• If you're stuck on where to go, try exploring further out into the world. Even if you don't find anything it the particular area you look, this will still be worthwhile, because...

• You will be expected to level grind. Regularly. Exactly how much you do so is up to you, but if you feel like you're hitting a brick wall, you probably are.

• Floor tiles that autospawn enemies every time you step on them are a great place to grind, if you're confident you can repeatedly beat the fight. You usually find them in front of valuable chests.

NES-Specific

• Consider using the Final Fantasy Restored romhack, if it's an option for you. It adds a few QoL features (namely faster combat, a dash button, and a 'Buy 10' option in item shops), fixes many of the game's bugs, and improves the translation. It also does all of this without softening the game's edges or chipping away at too much of the old school charm.

• You start unarmed and naked. As soon as the game begins, go into town and buy yourself some spells and equipment, and don't forget to put them on.

• Mobile healing/save items like TENTs and CABINs are bugged, and save before restoring your HP, so either just use them for freshening up before you enter a dungeon, or use a second TENT afterwards to properly save your improved status.

• In combat, HEL2 mistakenly has the effect of HEL3. It is, unsurprisingly, the best midcombat healing spell in the game.

• Skip the following spells: LOCK, TMPR, LOK2, and SABR. They're glitched and do nothing or worse.