As part of our new interview series, My Happy Home, we sit down with Martin Roberts to find out about the best decorating advice he has ever received — and why he loves a bargain at B&M. Martin is a property expert, author and journalist who has been presenting BBC One’s daytime property auction series, Homes Under the Hammer, since its inauguration in 2003. He has also written two books, Teach Yourself Making Money from Property and The Property Auction Guide, and is a guest presenter on The Jeremy Vine Show which airs on BBC Radio. What makes you happiest at home? MR: Cuddling up on the sofa with my…