Whenever we start a DIY project, even if its just a small repair, we start by protecting the surfaces in the room. Remove any furniture near the area you are working on. Lay a Seriously Good Cotton Rich Dust Sheet to prevent any dust, drips or spills from ruining your floor or furniture.
To keep you safe from tripping we also recommend using some masking tape to fix the dust sheet in place. This will also stop paint from bleeding through to the floor or skirting boards below.