Easy experience in Generation 1:
After defeating the Jumbo Cock Boss in the Cave of Origin during Generation 1, go back down into the Boss room in the dungeon and encounter the Boss again during random battles. Be cautious as he can also spawn with up to eight other monsters. You will be rewarded with experience, gold, TP, and EP for winning the battle faster. Save the game after each fight so you do not lose your levels, since this battle can go bad very quickly. Also, this is the only room you can find Mandrakes which is required for the Cave of Origins Title located at the Adventurer Hall, the requirement of which is to kill fifteen of each monster in the dungeon.
In Title Only - Make sure to check your titles. You can acquire titles at the Adventurer's Guild in town.
The More The Merrier - Execute a coordinated attack with six characters.
Alchemical Aptitude - You have added an item to the shop. Keep doing alchemy to add more.
Can We Keep Him? - Captured a monster.
I've Created a Monster! - Combined monsters.
We Can Rebuild Them - Created three marionettes.
Special Delivery - Used your first Special Art
Well-Read - Every profile is not available.
I've Seen Everything - Every item in the gallery is now available.
The First - Cleared Generation 1.
The Second - Cleared Generation 2.
The Third - Cleared Generation 3.
The Fourth - Cleared Generation 4.
The Fifth - Cleared Generation 5.
For Real This Time - Saw the true ending.
Titular - Earned every title.
Consummate Consummator - Earn all Bronze, Silver, and Gold trophies.