Minecraft

This achievement is currently glitched and would require you to apply 8 armor trims.

But, as of writing this, it requires around 15.

To begin, we can watch my guide on the achievement:
I cover all 8 that are required.

BUT, the silence trim and ward trim from my guide don’t seem to be found.
The other 6 do.

Ok let’s cover what we know:

Ward Trim - ancient city
Silence Trim (RAREST) - ancient city
Vex Trim - woodland mansion chest
Snout Trim - bastion chests
Rib Trim - nether fortress chests
Tide Trim - elder guardian death
Wayfinder Trim - trail ruins, using your brush.
Spire Trim - end city (mainly in the ship)

Now, those 8 are required, but in the case that the achievement doesn’t pop, you can find the:

Host Trim - trail ruins
Sentry Trim - pillager outpost chest
Shaper Trim - trail ruins
Raiser Trim - trail ruins
Coast Trim - shipwreck chests
Wild Trim - jungle temple chests
Dune Trim - desert temple chests

…so that it equals 15.

But worry about the main 8 FIRST!

Following my guide is quite easy.
SEED: 5705783928676095273

I use two seeds in the video.
One for the first 7 trims.
A second seed for the last trim.

In this case, you may not 2 of the trims on the first seed, so let’s collect what we can.

Follow the exact coordinates and movements in my video, getting you 5 trims.

Then, use the second seed in my video: 565535403532980236

…for the last armor trim (spire armor trim).

You should now have two left.

Simply search for ancient city spawn seeds for bedrock and just rinse & repeat.

BUT,

YOU CANNOT USE THE SAME SEED AND REPEAT IT.

ONCE YOU OPEN A CHEST ON A SEED AND YOU GET SOMETHING, NO MATTER HOW MANY TIMES YOU RE-ATTEMPT THE SAME SERD, THE LOOT TABLE WILL STAY THE SAME.
SO LOOK FOR DIFFERENT SEEDS FOR THE SILENCE AND WARD TRIM!

Follow my video thoroughly.
Hope this helps :)

Here is my 100% achievement plan for the 1.20 update. This specific achievement is found at 05:37 in the guide. I hope it helps.