The 'searching for the promoter' look
DJs of a certain pedigree have managers, agents and general industry lackeys to look after fine details like getting paid, getting pissed and getting some sleep when a night is all wrapped up. However, those on the lower rungs have to do these things themselves, resulting in moments of sheer panic five minutes from the end of their set when they realise the promoter has done one out the back door, leaving them stranded and penniless.
The skipping vinyl 'blame the tools'
Real DJs use vinyl. Real DJs would never let a record get scratched or scuffed. Real DJs take one step back from the decks and pull off a massive, highly visible shrug when their prized Underground Resistance 12" skips all over the place, causing the music to come to a juddering halt mid-set. Real DJs should always bring their own needles and never rely on the headshells at the venue that haven't been serviced since 1902. Because no-one is buying your attempt to blame it on a mini earthquake.