I don’t know if you’ve been using little or lots of dialogue in your stories up until now. We’re going to spend the next few days looking at dialogue issues, and play with a few different aspects of it.
Write a story that features realistic dialogue
When writing dialogue, remember that people don’t talk in speeches, not really. And they certainly don’t listen to each other. We interrupt, talk at cross-purposes and misunderstand each other all the time. Capture some of that.
When writing colloquially don’t go overboard with misspellings and missing letters to convey how people ‘really’ talk. Using ‘gonna’ and dropping the ‘g’ from ‘ing’ is fine if you’re trying to show that someone has a really strong accent, but invented spellings risk just making the reader impatient and irritated. Much better to try to capture the rhythm of a locale’s speech or use one or two tell-tale local words, than to try to transliterate a dialect accurately.
Remember to use sentence length to reflect how someone is feeling: short, choppy sentences for someone who is agitated; long, lugubrious sentences for contented fat cats.