Endear yourself to friends and family by playing my favourite game of all time, the titular 'wants a cock up it that one!'. Simply put, you utter said phrase at the most inappropriate juncture possible and wait for the people around you to react.
The above is a decent example but there have been better options in the past, the Queen's funeral, toothless widowed Ukrainian women, those adverts where people are told they've got cancer etc. Crucially, the person who you're going to say needs a cock up them must also be someone you'd very much not want to volunteer yours for.
In my view though you have to go some way to beat woman who's house is destroyed by a hurricane, wailing on her knees in mourning for her dead family, only to think she's found her dog alive but it turns out it is also deceased.
A bona fide classic. You wait til the volume of her screeching is reduced so that the news presenter, either at the site or in the studio, can sum up but just before he speaks you lean into the person next to you and spake those seven beautiful words. Fun for all the family!