Ni no Kuni: Wrath of the White Witch

Early in the game, you will gain the ability to take errands from Swift Solutions. There are 131 quests in the main game, and they come in 2 forms - errands (usually finding/delivering items) and bounties (defeating a boss-type enemy). There's no real need to keep track, but you should get Humanitarian of the Year about 2/3rds through the game, and Bounty Hunter during post-game if you're diligent about doing them.

You will receive anywhere between 1-10 stamps per completed errand depending on progress through the story and difficulty. 10 stamps fills a stamp card, and these cards can be traded for merit awards. You'll need to trade for every single merit award for this trophy, and there are JUST enough stamps to do it, so you'll need to complete every single errand in the game except for #131, which gives no stamps. Errands are always very straightforward, and you can usually see where you need to go by looking for glowing blue dots on the map. When you're doing the heart piece errands, the heart piece you need may not be in the same town, so be sure to look through every town quickly for those green dots that indicate people with heart pieces to take.

Since each tier of merit awards do not open until you've completed the previous tier, there's no need to worry too much about which awards you get first, but you should prioritize the ones for moving faster and getting better drop items.

This site (Errands (IGN)) shows every errand and what you need to do.

Errands tend to open up in batches after each section of the story. ALL available errands will be noted at the Swift office in every single town, either from the NPC or from the board, so you do not need to worry about ever missing any.

One warning: Errand 78 (available after beating the game) requires you to create an axe (recipe 60) for someone, and that axe uses VERY rare materials (Kaleidostone x5 and Scroll of Truth x5). Getting these 10 items took me 8 hours, and there are reports of it taking as many 28 for others. Here's how to farm them:

(If your level is too high, all normal (non-gold) enemies will run away from you. Cast Veil so that you can approach the enemies safely, and also guarantee a surprise attack)

Kaleidostone - In the Ice Grotto, there's 2 golden dragon Familiars, Dragamuffin and Bedraggle. You can steal the Kaleidostone from Bedraggle at a semi-low rate, and Dragamuffin can also drop the Scroll at a VERY low rate. To farm them easily, go to the final save point, then walk through the secret path to the left side where the rare purple chest is. There's 3 enemies there, and the dragons spawn at a fairly high rate. Kill them, walk back through the secret path to the small bridge, then turn around and go back to the left, and all 3 will have respawned. Repeat as needed.

Scroll of Truth - The hard part! There's 2 options - Miasma Swamp or Tombstone Trail.
- For Miasma Swamp, you are looking for golden Hog-Goblins (they carry an axe, vs golden Gobfather who carry swords). They spawn in the back of the level, so you can go to the final save point and just wander around until you see them, or use Veil+Levitate, walk to the end fighting any gold enemies you see, then Vacate when you get to the save point and repeat. Hog-Goblins drop Scrolls rarely (cannot be stolen), and Gobfathers can drop Kaleidostones very rarely.
- For Tombstone Trail, there's a section near the back where it's dark and you need the Magic Lamp spell. 2 types of golden bird Familiars spawn there, and you're looking for golden Honky-Tonker (with a keyboard on its head), who you can steal Scrolls from.

Sidenote: The DLC adds some new quests, but none of them give stamps for merit awards.