This thread has been really useful. I'm a FTB (hopefully) and it's given me a good idea of things to look out for/be mindful of.
As an HA tenant, I always left HA properties in pristine condition. The last time I moved, it was a home swap. The lady I swapped with assured me that the garden would be cleared (she had loads of stuff lying about in garden), and that she'd have the house cleaned (it was dirty). I left our place spotless. I also left: tins of paint so that she could do touch ups, spare lightbulbs, extra toilet roll, small box of tea/coffee/cookies, list of useful numbers for GP/local takeaways etc.
In the days/weeks before the hopeful move day (we planned to move on the day her/my kids went back to school after October half term), and before we signed all the paperwork, she kept on and on about how we needed to make sure we'd be able to move quickly as she had everything set to move straight away. I'd saved for packers/removals (I work FT and had two young kids and a disabled then DH) and arranged a week annual leave from work to get everything sorted. We then signed the paperwork. I kept asking her to agree/confirm date for moving. She went quiet. It then transpired that she actually DIDN'T have anyone to help her move, she couldn't afford to pay for a man with van etc, and hadn't done any packing. I only had that week, so hired a van (instead of just packers/removal company for me) and then spent the day moving her stuff one way, and my stuff the other way in order to get the move done. I could have cried.
We also had viewed her house/measured up when weather was better and doors/windows were open. When we moved in (November), I noticed (and couldn't get rid of) the strong smell of animal piss (it had soaked the lino in kitchen/hallway/bathroom). The house hadn't been cleaned and it was bloody filthy (and she left LOADS of her crap, plus additional piles of rubbish in the garden that she'd set fire to). She also failed to mention the huge flea infestation. Had I known about these things (particularly the flea infestation), I would have arranged for our stuff to go into storage, and us to go into a hotel, to have the bloody house deep cleaned and flea bombed, the garden cleared and then to give me the chance to rip out the piss soaked flooring. It was vile!
To anyone who does get flea/pest infestations....please just let new tenants/buyers know. If nothing else but to give them the damned chance to get a place treated before they move themselves and ALL their stuff in!!! It took me weeks to get everything sorted, and cost me a fortune.