Phobias come in many forms: Some people fear spiders while others fear flying on a plane.

But the one thing they all have in common is that they're irrational, according to one phobia specialist.

"A phobia is an irrational response to a benign substance," Christopher Paul Jones, a London-based phobia specialist with a clinic on London's Harley Street, told CNBC Make It in an interview.

"As human beings, we are primitively hardwired that when we experience danger, our amygdala fires off, and then we do one of several things. Most commonly fight, flight, or freeze. So, either get angry and punch the thing, or we run from the thing, or we hide from the thing," he said. The amygdala is a part of the brain that processes emotions like fear or motivation.

This trigger is handy when we were fighting saber-toothed tigers or if we were in actual danger, Jones said. However, a phobia is when that response is to something that isn't dangerous.

Jones' clinic has treated a variety of phobias from a fear of water, heights, germs, needles, and even the fear of failure.

He explained that phobias develop through a conditioned response like that of Pavlov's dogs experiment. That famous experiment was carried out by Russian neurologist Ivan Pavlov who would ring a bell every time he fed his dogs. The dogs eventually started to salivate when they heard the bell ring because they associated it with food.

"Human beings do the same thing," Jones explained. "Most commonly with a phobia, at some point in your past, your brain has linked danger to something that has happened ... then whenever you think about that thing again in the future, it fires off that old response."

Jones' recently published book "Face Your Fears" guides readers through exercises to help them overcome their fears. He shared his three top tips to overcome any fear with CNBC Make It.

Challenge your perception of the object

A very simple technique to challenge your phobia is to think about the object of your fear differently, Jones said.

He calls it the "Harry Potter" effect referring to a scene in the "Harry Potter and the Chamber of Secrets" movie where students face their fear and use magic to transform it into something comedic.

"So, when you think of that spider, often people make it very big and close up. If you imagine it small, black and white ... or imagine it on roller skates, smoking a little cigar, dancing with a little hand ... you're going to feel very different," Jones said.

He suggested using the same technique on your inner dialogue.

"If you're going 'Oh my god, I'm going to get scared' or 'This is going to make me jump' or 'What if I embarrass myself?' If you imagine that inner dialogue like it was Mickey Mouse or Donald Duck, with a squeaky voice it's going to take all the power out of it," he said.

In the moment, this will change how you perceive the fear because it will appear "sillier and less realistic," Jones said.  

Give yourself a hug

One of the simplest ways to comfort yourself when encountering the source of your phobia is giving yourself a hug, Jones said.

"If you basically cross your arms and go up and down your shoulders, like you're hugging yourself, it releases the same chemicals as if you were hugging someone else or if someone else was hugging you," he explained.

"This releases oxytocin and various other chemicals and what happens is, if you're doing anything that's relaxing or self-soothing while trying to picture the thing you're scared of, the brain struggles to hold two emotions at once, and so that emotion of fear will get reduced."

Recondition your brain

Jones referred back to Pavlov's dogs experiment and said that just as the brain can be conditioned to fear something, it can also be reconditioned to undo that fear.

"If you go to times when you felt really happy, calm or couldn't stop laughing and you just visualize those in your mind, and while visualizing those moments, you do something unique at the very peak of the emotion like squeezing your fist, thinking about happy times, squeezing your fist, thinking about happy times, squeezing your fist, you create an artificial Pavlovian response conditioning," Jones explained.

He said that if you then squeeze your wrist when facing a particular fear, it will take you back to those happy memories and take out the emotional intensity of the fear.

"Those are some very quick things, you can do to just disrupt that old pattern," he added.

"If you think about Reddit or YouTube, where people take like a horror movie and recut it into a funny film because they change the music and the pacing, we can do that with our internal images, internal dialogue, and our internal feelings," he added.