Last fall, I had the pleasure of meeting Duffy Brown and she presented a workshop on writing Cozy Mysteries. Here are the main elements that I picked up from her.
A Cozy Mystery is a mystery without the gore. Must have an amateur sleuth, who is sucked in because of a connection to the murder.
Typically there are 21 chapters with 15 pages to each chapter. Duffy plots the beginning and the end and then the middle... The Point of No Return is at the end of the 2nd chapter or the beginning of the 3rd.
All seems lost in the middle.
You must keep it current... Use twitter, cell phones, daily shows, etc. To give the reader and idea of what time period is taking place. Keep it relevant to the area of the country. Southerners act, speak and eat differently than someone from Main.
A cozy mystery doesn't have sex... (if they do it's behind closed doors... Though there might be sexual tension.) No cussing and no violence.
The amateur sleuth talks to the accused and listens to hearsay from others to collect facts in the case.
You should assemble your suspects in the 1st half of your story.
Remember it's all about the mystery. You can have other elements, but everything ties into the murder.
7 suspects, make some stronger than others. Also, the amateur sleuth has a good support system of 5 core people, who will be with her in other mysteries if you write a series. Characteristics for each character. Use different names... Duffy used Aunt Kiki, Doc and Boone to make them stand out.
Mentor, who is an older person, a cop or anyone who knows things. Your MC needs to talk over the clues with someone.
Write in 1st person, so you know what the MC is thinking.
Remember the police don't like amateurs getting involved.
You should tell your readers Who, What, Where, and Why in the 1st Paragraph.
Make it interesting enough to catch an editors eye.
Keep it Sharp, Quick and Young!
The MC always have a pet. Cats are popular, so Duffy used a dog instead.
Sometimes one of the characters will spout favorite quotes, persons, etc. i.e. Aunt Kiki quotes and refers to her days as a roadie for Cher. (Cherisms, Twainisms, etc.)
Ghosts are popular in Cozy Mysteries.
The story takes place in a quick period of time... A week or a month.
Remember no more than 15 pages tops for the chapters. Must carry the story forward.
Short scenes, quick dialogue and catchy titles.
Give your MC a hobby that will help him or her do what he/she needs to solve the mystery. (Being flexible helps, allowed to leave the job to follow up on a clue.)
Good jobs for your sleuth are graphic designer, consignment shop owner, book store ownere, etc.
Publishers give you a contract for 3 books at a time for a series.
I hope this helps all those aspiring to write a Cozy Mystery.
Good Writing and Good Luck.