I bought a mortar mixing cloth thingie from B&Q as I was working on the first floor, and mixing up mortar etc is usually a messy business, This is basically just a plastic coated cloth with four handles and a sort of skirt - a bit like a kids swimming pool. Allows you to mix up with no mess on the floor. Let the remains harden, and just sort of fold it up and they fall off. Only cost a few quid. One of those ideas I'd not thought of and bought on impulse - and proved worth its weight in gold.
Of course everyone here will know about them. ;-)