Get a trickle charger, cetek ones are brilliant, waterproof and will charge and cycle the battery for you so it's always in optimal condition, you can get fly away leads you leave it connected to the battery and it plugs in usb style, can leave the bonnet closed and alarm on too.
Pump up tyres a little more, say 35psi all round, even better get it up on axel stands if you can,
Buy a decent breathable all weather cover and make sure it's tied down properly crack a couple of windows let air circulate and buy some moisture absorbers (silica gell) put them in boot under seats etc.
Be wise to check for mice/animals once in a while too, sounds daft but it happens