There are few things that combine thigh-slapping hilarity and ninja-like sneakiness like an expert photobomb.

If you're looking to ruin the cherished memories of someone you've never even met before, mugging away like a loon in the background of that person's otherwise-lovely holiday snap is definitely the way to go.

Here are five essential tips to get your photobombing career up and running.

(Pics courtesy of This Is Photobomb)

01 Protruding is good

If you can appear to be protruding from someone's drink or bag, that's good. If you can appear to be protruding from someone's arse, that's next-level.

02 Do a "WTF yikes!" face

It's even funnier than sticking your tongue out in a piss-takey manner.

03 Wear a mask

Not only does a mask offer you total anonimity, it also adds a whole other layer of funny/creepy.

04 Leer through the window

Add a camera into the equation, and a sweaty-faced peeping tom suddenly becomes the greatest guy ever. 

05 Be a sea-animal

 As you can see from Mr Stringray above and Mr Hippo here, sea animals are the absolute dons of photobombing.