Oh yes, Martin Lewis, the 'expert'
A particularly dislikeable self centred idiot who thinks he's something special.
He's a very wealthy 'idiot' that sold his money saving website for £millions
Indeed

He has been very clever in his chosen field of expertise and made the most of it for himself, and as you say millions of us folk out here.
He has been a professional throughout and should be admired not degraded. 
.
I've done well with some of his advice, my mate has made himself £1800 over a couple of years by switching bank accounts etc on his advice , I couldn't do that fearing direct debits could be affected but he reckons he's had no problems.
You open another account with a bank you don't currently use. Then once that account is open, you transfer it every 6-12 months to someone. You may have to jump through a few hoops and setup DD's or pay in a regular amount every month, but it's all doable.
Leave your 'real' account alone - I've had my HSBC(Midland Bank) one for 40 years - but I've also got Halifax, TSB, Lloyds, Nationwide, and have had Abbey & Santander.