April marks the second anniversary of me directing commercials in America, the fifth anniversary of me directing commercials in the UK and the seventh anniversary of me directing, full-stop. Happy anniversary to me. I'd like a pint of bitter and a bag of your finest pork scratchings please, landlord!

The opportunity to become a director came about when I met the supremely talented Dom Joly with whom I made the TV series Trigger Happy TV. We wrote it together, produced it together and directed it together, it had a great soundtrack and lots of costumes and it was an incredible buzz.

Trigger Happy TV was ultimately an updated Candid Camera; it thrived on unsuspecting members of the public and was really a celebration of natural comedy in its purest form. We had no control over the participants, no control over what they said, or if they said too much, too little or in the wrong language. We had no control over how they reacted, if they reacted at all or if they simply stared straight at the camera; often they would pass by oblivious to our overt attempts to lure them in with silly outfits and teasing signs like 'CONGRATULATIONS, YOU ARE OUR 1,000,000th CUSTOMER'. We had very little control over the locations, the set dressing, the sound, or even the shooting schedule... and we couldn't do any take twice! I've had Terry Gilliam swear at me; a chimney sweep nearly have a heart attack in front of me; I've witnessed a nun's surprisingly hostile reaction to being accused of shoplifting and I've even seen an old-age-pensioner push Dom into a pond, yet oddly the performances from these strangers were always superb, perfect even. They were never too broad, too over-the-top, never too knowing, or smart - just great natural comedy.

A few months into filming the second series of Trigger Happy TV, I booked my first commercial as a director. The script was very similar in style to Trigger Happy TV. I can remember the shoot, crouching hidden in a bush, adrenalin pumping, my DV camera in hand as the actor walked down the street heckling unsuspecting members of the public with a compact megaphone. The only difference between this and the TV series was that there were about 60 people standing behind me, a catering bus, a trailer for the actor and a mobile toilet - all this to guarantee the exact same natural comedy three of us would create on TV.

My debut spots in America for Ikea were a comparable experience. They had a new store opening in the area and wanted to introduce themselves to the neighbourhood. Through an extensive casting period we found two really talented, funny and quick-thinking actors, put them in Ikea uniforms and went knocking on the front doors of suburban Minneapolis. I had decided we had to do this for real, that was my pitch, so in the two days of filming we knocked on 53 genuine front doors, trying to capture that unique moment of human interaction that you couldn't fault for its authenticity and was all the funnier for it. It was pretty tense - tinted SUVs, ear pieces to communicate, real seat-of-the-pants stuff, but the result was more than worth it.

Today I still find myself creating these moments although now I know how to utilize all the benefits of high-end commercial production without compromising the uncontrollable, spontaneous qualities from my Trigger Happy experiences. I'll purposefully keep casting briefs open to allow for a little chaos, upping the likelihood of some quirky, unique and memorable actor walking through the door; someone you could never have described on paper, but is the perfect fit. I also work with casting directors who really understand this approach, thereby avoiding the tedious procession of conventional, dull, ad-friendly beauties. On set, I'll try to create an environment where the actors feel confident enough to step into the spontaneous unknown. I'll hint at amusing small details and then step back and let them go for it.

A successful example from this approach came while shooting a campaign for AmPm. We had found two superb actors for "Indecision", particularly Jesse Meriwether who played the part of a girlfriend that couldn't decide which soda to choose in the store. Together we discussed this scene, sharing stories and ideas that might help and when it came to shoot I sat back and watched as she nailed it. In response to her impatient boyfriend rattling the ice in his empty soda cup, she spontaneously rattled her cup back at him. It wasn't too big, too small or too knowing - it was perfect.

These moments make me laugh a lot, which ultimately has been the goal over the past seven years. This type of natural comedy also seems to have great reaction with viewers and I'm always looking for new scripts that will allow me to create some more - but for now, I'll have another pint of Old Speckled Hen please, landlord!

Happy anniversary to me.

Cadman is repped by Tool of North America in the US and Rogue in the UK.

Sam Cadman> www.samcadman.com