PenStoryTeller

The Deus Ex Machina is typically a trope born of poor planning , tight deadlines and frustration as much as it is lazy writing. A Deus Ex Machina like any writing tool, can be used to great effect. The greatest rule I’ve heard is that. COincicdeence and Chance should never solve problems. They may change the problems but if they solve the protagonist’s problems. It invariably trivializes the struggles of the protagonist. Worse,coincidence, chance, happenstance and deus Ex machina’s occur too frequently… it jettison’s the reader out of the experience.
Too see deus Ex Machina done well. I’d recommend Reading A Spell for Chameleon by Piers Anthony.   But let’s take Tolkien’s The Hobbit. Bilbo finding the ring could be seen as Deus Ex Machina right there. But note. The ring does not actually unilaterally solve Bilbo’s problems. It merely gives him a tool to assist him in figuring out solutions to his problems. By itself the RIng is as much a risk as it is a boon.. One might also see the ruscue by the eagles as Deus Ex Machina, but again it doesn’t really solve their issuesso much as deliver them from one problem to another, and initially Bilbo isn’t certain if the Eagles are helping.   See how that works?   One trick is to make someonthing seem like Deus Ex when actually  it’s something that you’ve been subtly dropping clues about:   The protagonist is told about the age of the buildings in a particular part of town.  ANother chapter someone off handedly remarks that a great fire in the cuty destroyed all but a few of the oldest wooden buildings.   IN another chapter, mention the unusually rainy and humid season, they;ve had the last few months.   SO when the wooden roof of the old chapel collapses during the climactic chase scene, allowing our heroes to escape. An astute reader will probably remember those tidbits, or pick them up during the second read through. Of course, the Chapel must have been one of the buildings that was spared in the fire, so the wood was very old, worse still, the ususually rainy and humid conditions would promote or accelerate rot in the old wood. STill random that it chose then to collapse but it';s not like a tree branch announces that it’s going to fall on your car during the night.   If you need too use a Deus Ex Machina. Use it early in the story. Let it be part of the inciting incident. If you write your characters into a situation that you need to use a deus ex machina to get them out… then you’re not playing fair with the reader. The reader’s mind will shift from, “How will they get out of this situation” to “How will the writer get them out of this situation.”

If you want to leave hints and clues to your mystery, then you’re playing a  dangerous game. Keep them subtle enough that the reader will recognize them in hindsight rather than use them as foreshadowing.
 
Or in other words. Make your clues subtle enough that the reader won’t see it on the first read through but will recognize things during the second.  The best clues are usually not what you show happening, but rather just alluding to something that happneed off page.
Having the main character notice a tear in the cuff of the butler’s sleeve. Have an off hand comment that  the woman was seen talking with someone named Marcus.

Easy. DOn’t overthink it. Go with the combination of phonemes that create just the right emotional impact you’re trying to go for.

No set process. I just pick whatever rolls off the tongue. If I get thoughtful about it. I ask myself. What did their parents name them. Which gets me thinking about the background of the parents and the family upbringing.
 
I rarely do that anymore since the name, is basically the most unimportant part of the character. You can name a character anything.A great souding name will not save a poorly written character.

What is the purpose of your antagonist.Are they soimply an obstacle, or are they meant to be a straw man, or reflection of the hero? These are the sorts of questions you need to ask.
 
Best advice I’ve heard.?
Treat and write your antagonists as if they were the protagonist of a different story centred around the same events. That will generally get you thionking about them interms of who they are and why they are as opposed to them being convenient amorphous plot-spackle .