Dialogue is probably the best way to make readers really get to know your characters. It also gives your writing variety and speeds up the pace (because, as with metaphors, a few words reveal so much) which keeps it more interesting.
Here are a few tips to help you make your dialogue effective:
1. Use realistic words. One reason why dialogue is so interesting and characterizing is because readers get to “hear” characters speak and instantly get an impression of what they’re like. If you don’t quote them the way they really talk, this won’t work.
If a teenager is speaking, don’t be afraid to spell words like “gonna” and “wanna.” If a drill sergeant is speaking, you may need to sw#@r.
2. Only say important things. If you can explain something faster without dialogue, then just explain it. Save the dialogue for interesting ideas and to show attitudes that characterize.
3. Describe the characters. If readers can picture them, it makes their words much easier to hear in their minds. Age is one of the most important things to reveal if it’s not already obvious.
4. Describe action. Along with the words, describe body language and facial expression to help readers interpret the words the way you intend.
5. Describe reaction. If someone says something shocking (or boring or whatever), then describe how others react to those words. Not only does this help convey the thoughts and feelings you intend, but as readers read these reactions, they will imagine the reaction and thereby experience the reaction in their minds!
Find three more tips in The Art & Craft of Writing.
In case you’re not familiar with how to punctuate and format dialogue, this next section should help you. For print formatting, pretend each of the following paragraphs is indented half an inch, which doesn’t work as well online without some special coding.
Once upon a time, there were two characters named Chris and Kirsten.
“Hi,” said Chris, “I’m Chris.”
BTW you can spell the word both “dialogue” (UK & US) and “dialog” (US).