Thompson began his martial arts training in the Eastern arts including karate, Aikido and Kung-Fu. However, during his time as a nightclub doorman he found that what he had learned was inadequate for the reality of violence. Thompson came to realise the techniques encouraged and practised in touch contact and semi-contact martial arts were not always suitable for self defence. Though he utilizes a small core of techniques from touch contact and semi-contact martial arts as part of his teachings, Thompson prefers more pragmatic full-contact martial arts and combat sports such as boxing, kick boxing, Muay Thai and wrestling (Greco-Roman, Judo, Jujutsu and Freestyle).

He holds the ABA boxing instructor certificate and high level coaching awards for wrestling. as well as a 1st Dan in Judo, and 6th Dan in Shotokan Karate.

Geoff Thompson was also the first instructor to name and extensively teach "the fence" a revered technique in real life defence involving keeping your hands in front of you in a non threatening manner so as to protect yourself if a situation escalates but without provoking violence

In addition to his books, Thompson has written and presented a series of martial arts and self help DVDs. In 1995, he and his self defense school featured in the Channel 4 documentary Passengers. In 2004, Thompson won a BAFTA award for 'best short film' for his screenplay "Brown Paper Bag".His short film "Bouncer" starred Ray Winstone.

His most recent work "20" directed by the Shammasian Brothers and starring Craig Conway has finished production and was shown at a private screening in London on 23 January 2008. It toured the film festival circuit in the early part of 2008.

Thompson's first feature film Clubbed an underworld drama set in the early 1980s has completed production and is scheduled for release in the United Kingdom on 16 January 2009.