Best method to find diamods

Diamonds are finding between x 9 - 13.Just try this

Imo, stripmining at height 11 is the best way

Baritone if you count hacks.
And maybe the clay trick without modifications.

i reccomend to crawl(feature in newer versions) and strip mine at y= 10. Just get a trapdoor and put it to wall, get under it and then close the trapdoor. This will get you in the crawling position and you can strip mine to any x or z location. Of course luck always matters in mining.

//replacenear 50 stone diamond_ore

strip mining has always been my go to

Dig down to y 10 to 16, strip mine around and you should be able to find some

keep digging gugs perfect to go down to 13/15

Stripmining at y11 or y8 is the go to for me

With the new update it's in one hand easier than ever. Dig down and find the big caves. Diamonds are like everywhere visible