NON permanently decorating/insulating a rented house

[hangingoutattheendofmywick]

It looks like we are moving to a rented house that is perfect in location & size - But it has two defects:
1: it's got hideous decor (not every room but the kitchen literally hurts my eyes) and
2; it's absolutely freezing.

So my question is two fold:
1/ how can I improve the appearance of the house but only in a non permanent fashion? (The kitchen has horrendous tiles on the wall and vile cupboard doors) and
2/ how can I make the house much much warmer?

So far my ideas are:
Those double glazing film things for Windows.
Make curtains with fabric lined with fleece.
Huge rugs from Ikea

I'm willing to spend a bit but we aren't allowed to say - rip off the disgusting tiles and re-paint the place.

Any other ideas?
Thank you

[TheCountessofFitzdotterel]

Reflective stuff behind any radiators that are against walls.
Draft excluder of whatever kind round the windows if appropriate.
I suppose the real question is why is it cold.

[IdaShaggim]

Could you use some kind of contact paper over the tiles?? Would disguise them, but be relatively easy to peel off as and when you moved out or fancied a change?

[hangingoutattheendofmywick]

Ooh yes that's a good idea