Speak to the Katz at the Izoold docks.
Rewards
Easy: 5 Apple Gels
Normal: 5 Life Bottles
Hard: 5 Lemon Gels
there are no titles awarded here, but the rewards for winning can be helpful early on, if you don't hate the game
MISSABLE
Speak to the man behind the counter in the Palmacosta Academy cafeteria, after buying the Palma Potion or Cacao recommends working there.
Rewards
Colette's Turbo Waitress title
100-500 gald, depending on how you do
it may be helpful to write down orders or otherwise record them. there's no timer on getting orders out
MISSABLE
Speak to the guard in the Palmacosta square, after defeating Kilia.
Rewards
Finish in under 1 minute: Lloyd's Palmacosta Pro title (Chronicles Only)
you might need to play a few times to get lucky with checkpoints
checkpoint guide incoming
Speak to the Katz on the Grand Tethe'alla Bridge (the side near Meltokio).
Rewards
Genis' Strategist title
After opening the gate to Vinheim: One World
you need One World for Genis' Item Collector title, and i don't recommend struggling through this twice, so unless you enjoy this (why?), come back later.
if you pause while the Katz is turning around, you won't get caught moving.
the other kids will hit you less if you're on the outside.
good luck
Speak to the man in front of the Triet inn, after clearing the Remote Island Human Ranch.
Rewards
Identify 100 uncles and clear High Speed Mode: Lloyd's Midlife Crisis title
they won't start racing until you hit a button, it may help to write down the men then number them as they come in.
you're timed while you pick them, but the timer doesn't run while talking.
later levels get crowded, be careful you're talking to the right man.
good luck