What we are dealing with this week concerns accents, an extension of social fabric!
Accents are one of those things that many writers struggle with. I can say that because I myself struggle with accents. Creating a convincing accent is not so much an exercise in creativity but also diligence, because your characters must commit to their voicing for the duration of the book. Cultivating these accents is tough work, but I've prepared a few things to consider when creating accents that can help give more cohesion to your universe.
Before when we were talking about social fabric, I tried to emphasize that different classes or demographics of the community will determine how your society develops. Accents are another means of distinguishing those classes from one another. When creating an accent it must make sense in the context of the world that has been created. England alone has over 25 dialects of British English, and that's not including Ireland, Scotland, or Wales. These differences have arisen over time because of the incredible diversity and historical history of England from the Romans up to the Norman invasion in 1066. If you choose to have accents in your story, they represent a cosmopolitan history.
Accents as I mentioned before can emphasize the distance between upper and lower classes. How your characters speak will determine this. In England, a journeyman's accent is vastly different than a politician. The way a lower class person speaks in your book should showcase the corruption of the language of the parent culture. This reflects a lackadaisical attitude or a lack of education. For Example, I will create two dialects, one high, one low, and you will compare them.
"Stripped, battle weary, the men fought as hard as they did m'lord, with pryde and honor."High:
"Naked and hardened by war, the platoon stood their ground, brave and worthy of commendation."The low accent is characteristic of a class that is not the reigning power. The diction is much simpler with words lacking in syllabic complexity. Slang usage like "M'lord" shows a corruption of "My lord" and the use of the archaic spelling "pryde" infers that the usage is more traditional and older. The high dialect distinguishes itself from the low here by using words that are more cosmopolitan, illustrating an awareness of international community, a mark of maturity and developed national identity ("platoon" and "commendation"). Also the pacing at the beginning of the sentence shows a more developed thought contained in the sentence and illustrates a better command of grammar.
Absolutely critical to creating a homespun accent in your book is demonstrating consistency in the accent. If you create a character who drops the "h" in their speech (pronouncing "Hat" as "at"), that character must continue to do so throughout the length of the book. This may seem a bit of a no brainer, but doing this over the course of 500 pages is incredibly difficult. My best advice on how to make this work is research the dialect you want to employ in your book. After you have cultivated your own dialect or thoroughly looked over an existing one, take note of the rules of speech. Using the silent "h" rule above, every time your character speaks, employ the rule. As long as you approach this analytically, you will remain consistent.
Wikipedia actually has a lot of resources on dialects that I found exceedingly helpful in building the dialects for my book. I would definitely consider taking a look at their list of English dialects especially for their thoroughness.