Item description:

Here we have a nearly full Platinum trophy set for [EU] THE LAST GUARDIAN [CUSA03745]!

(Unfortunately this can not be re-regioned to [US] or [AS] at this time. You can always buy a European version online though -- like I did)

STEP 0: Blind Playthrough (Optional)
To start with, I would suggest you play through the game from start to finish without using any of these files. You may get a few of the combat-related trophies, or the tricky 'Call of Nature' trophy on your own.

STEP 1: Speedrun, Unlock All Hints, All Barrels, All Costumes, All Trico 'Holes', All enemy beasts
The following save file comes courtesy of user Saman80 STEP 1 SAVE FILE

STEP 2: Intensive Care
The following save file comes courtesy of user aon1 STEP 2 SAVE FILE

STEP 3: The Call of Nature & Platinum
The following save file comes courtesy of yours truly STEP 3 SAVE FILE

Trophy list and details for unlocking:
Spoiler:
The Last Guardian
Platinum. Unlocks when every other trophy has been obtained.

Though We Are Far Apart
Load Save 1 or 2 and defeat the final AI. Alternatively, unlock this naturally in Step 0.

Lightning Emissary
Load Save 1 and defeat the final AI.

Fleet Emissary
Load Save 1 and defeat the final AI.

Spry Emissary
Load Save 1 and defeat the final AI.

Untouchable Emissary
Load Save 1 and defeat the final AI.

Lock, Stock, and Barrel
Load Save 1 or 3 and begin a new game. Give Trico 1 barrel for this to unlock.

All Talked Out
Load Save 1 or 3 and begin a new game. The narrator will speak to you early on in the game and unlock this.

Dressed for the Fest
Load Save 1 or 3 and choose Items from the pause screen. Equip one of the boy's outfits to unlock.

That Hits the Spot
Load Save 1 or 3 and begin a new game. Hit 1 suit of armor with a barrel to unlock (roughly 30-60 min into game). Alternatively, unlock this naturally in Step 0.

Losing Their Minds
Load Save 1 or 3 and begin a new game. Knock over a suit of armor and pull his helmet off to unlock (roughly 30-60 min into game) [check youtube if stuck]. Alternatively, unlock this naturally in Step 0.

Get Off My Back!
Load Save 1 or 3 and begin a new game. Get behind a suit of armor and jump onto its back. Hold on for 30 secs (roughly 30-60 min into game) [check youtube if stuck]. Alternatively, unlock this naturally in Step 0.

Thundering Wonder
Load Save 1, 2 or 3 and begin a new game. Find a suit of armor attack it with Tricos tail lightning once able. This occurs late in the game. Alternatively, this is done quite naturally in Step 0.

Last-Minute Reprieve
Load Save 1, 2 or 3 and begin a new game. Let a suit of armor pick you up and have Trico kill it (roughly 30-60 min into game). Alternatively, unlock this naturally in Step 0.

Beast Friends Forever
Load Save 1 or 3 and begin a new game. Select the painting tool from the Items list in the pause menu. Use this the way you use the disk to paint Tricos body a different color.

Practice Makes Perfect
Load Save 1, 2 or 3 and begin a new game. Feed Trico a barrel by throwing it to him and having him catch it in midair. Alternatively, unlock this naturally in Step 0.

The Call of Nature
Load Save 3 and select continue from the main menu. Once game has loaded do not leave the area you start in. You want to run back and forth from the entry stairs to the interior stairs, each time breaking Trico's line of sight with you. There is a grassy patch in this area that he should stop and smell. What you want to do is hide behind a pillar and wait for Trico to walk over to you. As soon as he does this, run past him out to the entryway stairs and hide again. Do this over and over and he will do his business. Worked for me twice in ~5 minutes. Alternatively, unlock this in Step 0 with a bit of luck.

Balancing Barrels
This must be done legit. Either load your own game or one of the saves above and find two barrels right at the start of the game. [check youtube if stuck]

Keep On Running
This must be done legit. Either load your own game or one of the saves above progress through the game until you reach an antenna room. [check youtube if stuck]

Broad-Backed
This must be done legit. Either load your own game or one of the saves above progress through the game until you reach the arena area. [check youtube if stuck]

Cryptozoologist
This trophy is achieved by grabbing all of the evil Tricos in the game. Saves 1, 2, and 3 should all work to unlock this trophy after grabbing the first one you are able to. This is untested. Alternatively, you can unlock this naturally in Step 0.

Intensive Care
Load Save 2 and complete the final battle with the evil Tricos and AI. Unlocks after end of credits.

Collar
Load Save 1 or 3 and start a new game. You will unlock this once Trico puts his head into any hole.

Lifeline
This must be done legit. Either load your own game or one of the saves above progress through the game until you reach an area where this can be farmed. [check youtube if stuck]