I know there's a STICKY up ^^^^ there about writing accents, but I came across this yesterday and found it helpful.
Dialogue in Fiction.
Dialogue in Fiction.
I think less is more when it comes to "writing" accents.
They say the words, and I might select the phrasing to "sound" Irish -- "I'll just be checking that for you now" and "a wee dram" -- and the other characters will observe internally that the words are accented. Other characters in this same novel have Hispanic heritage, but rather than belabor that in the pronunciation of their English words, I slip in a Spanish word or two: hola, abeula. I think that's clear enuf for the reader while not laying it on too thick.
Accents are caused by the influence of a speaker’s native language or native dialect on the English words they speak. The differences can be found in pronunciation, diction (word choice), syntax (word order), grammar (how parts of speech are structured), and idiom (peculiarities of certain phrases). Accent and dialect can convey differences in ethnicity, geography, demographics, class, education, and culture.
I think less is more when it comes to "writing" accents.