Improvisational comedy first became widely popular in Britain with the success of Whose Line Is It Anyway? on Channel 4. Josie Lawrence became one of the longest running cast members, appearing for the first time in the pilot episode, all the way through to appearing on the American show ten years later. Jim Sweeney became a semi-regular cast member during the third series and continued to appear on the show for a further three years.

However, this was not the first time Lawrence and Sweeney had worked together, in fact their first meeting had been her introduction to the world of comedy and improvisation; whilst she was playing a manic depressive Glaswegian in a play at the Donmar, Jim was performing late night cabaret and improvisation directly afterwards. After watching the show, Josie was hooked. To her delight, she soon became a member of the team with Jim and they continued to work together on a regular basis on stage, such as the Rupert Pupkin Collective. They have both been members of the infamous Comedy Store Players since the 1980s and, although Jim retired from performing in 2009, Josie can (at the time of writing) still be seen on stage, with the rest of the troupe, twice a week at the Comedy Store.

They continued to work together on stage and radio for twenty years from that first meeting, including the improvised historical drama The Masterson Inheritance, which was devised by fellow Player Lee Simpson and ran for three series on Radio 4. Despite their long history working together, The Lawrence Sweeney Mix will probably be their last, with Jim retiring due to developing Multiple Sclerosis.

The chemistry between Jim and Josie is what makes The Lawrence Sweeney Mix the success it is; the comedians are always looking for a way to catch one another out, but their friendship and mutual respect is always apparent. Josie sets the tone in the first sketch when she puts Jim on the spot by asking him to recite a non-existant poem. Their playful banter continues into later episodes; when Josie gets stuck defining an affectation for the audience she places the onus on Jim. Their efforts to corpse one another combined with bold jokes and strong characterisations provide a quick moving and well rounded show. Whilst they set about to corpse one another or highlight mistakes they have previously made, there is always a sense of warmth that can only be found in a group of performers who know each other so well. In one sketch Jim - playing Josie's young son - is asking his mum why the sky is blue. Josie's soft, caring tone disappears and she retorts "How the hell should I know? Shut up and eat your tea!" Jim tells the audience that we're getting an insight into the Lawrence psyche. Josie quickly agrees that she doesn't have children, she has cats!

The length of the sketches is not pre-defined and they vary from piece to piece. Some sketches are very short and snappy, particular highlights are about sudoku or queuing for parsnips. Others become as long as four or five minutes with detailed plot and characters, such as a visit to the Moon or getting trapped in a Portaloo. Each sketch is dependent on the quality of the audience's suggestions - something which Jim is quick to point out - and they range from the mundane (the perfect shed) to the obscure (camel wrestling). On the odd occasion that a sketch lacks direction and they let it drag on too long, the players are the first to recognise this, quickly deriding themselves. This honesty and good humour always shines through; when Josie makes a cheap joke to create an easy ending, Jim instantly retaliates by ridiculing her lapse into immaturity. By making a joke out of their mistakes, they make what could have been awkward into a memorable moment.