Gala reminded me today of the lovely household shop SIA. There's a branch in Termini station, ground level, in Rome. Also apparently one in a Rinascente, (whatever that is), in Florence. Very expensive though.
sia - HOME FASHION - Italia
Other recommendations include Banak Importa Their website I see hasn't been updated though. You can find them at the shopping centre beside Roma Anagnina IKEA.
Banak Importa
Coin Casa which is part of a chain departmental store Coin and prices there are reasonable. There is a huge branch in San Giovanni in Rome but scroll down the page for other addresses. Their online shopping facility seems to offer different goods than that in store.
Coin - news - Discover the Coincasa Fall Winter Collection
However times are hard and luckily IKEA this year are great for decorations, cards, wrappings and of course Christmas trees, A very large bottle too of Glug will only set you back a couple of euros. Their sale begins here in the UK on the 18th December so I reckon around that time in Italy. They have already reduced some of their decorations!!!