Where are you located? Unless you're in the tropics, about all you can use are things like pine boughs and the like.

HI -- What about some of those large L.E.D. outdoor light balls with some greens to fill in . Or some white bark branches with evergreens and pine cones . Or if it's below freezing -- colored water frozen in plastic buckets and turn the ice block out into the pot and then fill in around with some outdoor lights . There are lots of decorating ideas on Houzz and Pinterest and Google and Youtube .