When not in 'Smithy' character, act normally, which is just like 'Smithy' character
Borderline homo-erotic behaviour is essential
Face-palm plenty and talk quietly when upset/angry
Over the top passion when happy
Talk in high-pitched voice when attempting to stress something important
Break dancing or a subtle reference to 'the robot' always helps if extra laugh is required
As much over-exposure on TV as possible, before the bubble bursts. If it's football related, get on it to consolidate yourself as the new face (and gut) of English football celeb-punditry. Fat is funny, in ads, on panel shows, footie post-match commentary and anything with celebs in it
Release a collaborational England song (everyone else is doing it, so why the hell not?) because this further increases your profile as a celeb that loves football (note: don't wear a West Ham shirt in public, there's no money in it)
Reveal your belly at any given moment, for larfs
Follow the Ricky Gervais Guide to Offending Other Celebrities in Public but in a funny 'joke way'
Thank God each night for that Comic Relief team talk to the England players that kick-started the post-Gavin and Stacey work-load (because the Horne and Corden Show doesn't really count, does it?)
In a nutshell, just continue to do 'Smithy' until you end up back as Smithy in a Christmas Special, thus coming full circle and ending the journey by completing an Ouroboros on ones self