When you’re selling an apartment, the communal areas are invariably the first impression a buyer will get of your property. So unless your building is always pristine, take a walk around - outside and in – and note what you see.
Some things, such as maintaining the gardens, changing light bulbs and cleaning the stairs, might need to be brought to the attention of the owners’ corporation, but as they can be notoriously slow at attending to such things, it could be worth your while to take to the lobby yourself with a mop and some glass cleaner just before prospective buyers arrive.