Here’s An Elementary Cheat Sheet For Solving Crimes Like Sherlock

Take a sniff.

Take a sniff.

You might not want to smell a crime scene, but sometimes a lingering scent is a clue. A strange scent in the air could point you towards a killer, whether it’s the unpleasant scent of model airplane glue or the pleasant smell of pumpkin pie baking. Either can point to how a victim met a bad end, though you’ll never quite be able to enjoy the scent of nutmeg in the same way again.
How stupid is your suspect?

How stupid is your suspect?

Sometimes the clue you’re looking for isn’t a cleverly laid plot, but a not-so-cleverly laid plot. If your suspect is just too smart to have pulled a particularly dumb move, you may well be looking at the wrong suspect. After all, if it was a simple crime, you wouldn’t be involved in the first place—the person who seems dead guilty might be the victim of a frame-up.
What isn’t it?

What isn’t it?

Sure, it’s important to know just what your crime is, but it’s equally important to know what it isn’t. Is a crime scene set up to appear to be something it’s not? Is that suicide really a suicide? Is that accident really an accident? Or does someone just want to make it look that way? You’ll want to take a close look for anything that doesn’t quite fit in with the scene to make sure your crook isn’t trying to trick you.
Ask for help.

Ask for help.

Being a consulting detective means you need to be an expert in many things. But you can’t know everything, which is why it’s important to cultivate a network of experts to lend a hand when needed. This means cultivating your own network of irregulars, from mathematicians to geologists to a hacker collective who can offer the expertise you need when you need it. If you’re lucky, your experts will be happy to help for the intellectual challenge of it. 
Whatever remains must be the truth.

Whatever remains must be the truth.

You may be tempted to find the obvious solutions, but they aren’t always the right ones. When evidence contradicts the easy answers, you have to be open to the more improbable (or even impossible) ones. And when you’ve eliminated even the impossible answers, whatever remains must be the truth. That’s the case even if that’s killer mosquito drones or poisoning by impossible-to-induce diseases.
Look at things in a different light.

Look at things in a different light.

It’s impressive how often our intrepid detectives run into invisible ink, but run into it they do. That can include invisible ink stains proving a murder, secret math proofs written on walls, or government secrets hidden in tattoos. Shedding light on the situation not helping? Try looking at it from a different angle, instead.
Pay attention to things that literally don’t line up.

Pay attention to things that literally don’t line up.

We’re not talking about facts—though when they don’t line up, it can be a problem, too—but actual physical objects. Do wall-hangings line up properly? Do arrangements of paintings or furniture match the evidence found in photos or dust marks on the floor? Sure, not everyone arranges items in his or her house using a ruler and a level, but items being off from what is expected is often a sign something’s amiss. Though, you’ll have to find out for yourself whether that means a body hiding behind a wall or a stolen piece of furniture.