I've had two lodgers in the past, kinda new them both but not well before they moved in.
Bith were a nighmare, mainly never pay rent in time or only partially paying.
I made the mistake of doing it with no written agreer or standing order set up, so id be chasing them for money, they gave silly excuses, (both worked full time and I was charging £300pcm all inclusive) and I ended up getting so stroppy with them they ended up moving out.
Other annoyances included using the tumble dryer constantly, not caring about power consumption generally, overall more hassle than they were worth.
There was a catalogue of other annoyances, one of them was a 'chef' at Witherspoon, and damaged all my non stick pans by using metal utensils with them, boiling pans dry with rice/pasta, I could go on, nothing major and nothing malicious, but just a general lack of care and diligence, and things that cost money to replace.
But I guess it really depends on the individual, I just got unlucky.
Id recommend making anyone sign up to a standing order, and build into the price enough to cover wreckless use of gas and electric, as if the bill is not in thier name they seem to treat it as a free resource.