Themed Christmas trees have grown in popularity over the last decade, although I have a large tree filled with various ornaments collected since I was a child. I have many themed trees throughout my home, yet they are all smaller in scale to be used as accents (plus, who has that kind of room in their home....not me)
When considering a themed tree, think about what you are passionate about - maybe bird watching, what people know your for such as baking, a favorite place you like to go, i.e. your cabin or maybe a favorite color. Make it personal, so there is a story behind the tree which adds depth to the decoration. I have one filled with vintage ornaments which reminds me of the ones my grandmother had on her tree.
When it comes to creating a themed tree, recognize that this may take some time, hunting and gathering (even Googling) - many of my trees took years to come together after finding the ornaments first or the tree, then looking for the rest to finish for years at times. I'm working on three right now that has been three+ years in the making - it requires patience.
The baked goods and cabin-themed ornaments were all found at Macy's (in-store, not online) 2015