Well, we always decorate the rest of the house before we put the tree up....we like to cut a tree & do that closer to Christmas. But I'm such a big baby when it comes to Christmas that I can't wait until the week before!
We do put a garland in our doorway between the living room & dining room. It's a wide/double doorway with moulding around it. I put white twinkle lights in it, some red tinsel garland & my heavy ornaments that won't work on the tree. Everyone who comes in comments on it - I just love it!
I have a big dry sink that I clear out of all my "normal" stuff & fill with our collection of Santas. I have a side table that gets a Christmas-y runner on it & one of those big things that spins around from the heat of the candles? I don't know what it's called. DH calls it the carousel.
I have a wall with a grouping of various pictures, a small mirror & other country-type wooden "things". Those come down & it gets replaced with our collection of similar shaped items that are Christmas themed.
DH has a collection of nutcrackers that he puts in the window sill. (We live in an old stone farmhouse with 18" sills.) In another DD puts her wooden creche/nativity set, which is quite large - as in number of pieces. We have a Moravian star that hangs in that window at Christmas too. I have electric candles in each window year round that we leave there as well. I usually change the bulbs to the ones that flicker for parties & such.
We have a variety of little wooden ornamental items that we find spots for all over the house. On top of the hutch over the computer, we wind tiny white lights through the stuff.
I have a "basket tree" that hangs from our drop ceiling. A couple years ago DH put white lights in there at Christmas. But we liked it so much we leave them in year round. We spruce it up in the fall by putting Indian corn in the baskets as well as some small plush things that fit. At Christmas we take out the corn & put in pinecones & switch for small Christmas plush things & even have some handmade wooden ornaments that we hang on the ends of the hooks.
Candles go everywhere. I'm currently working on replacing all of our Christmas candle rings. Our old ones have been around for 20+ years, but I hate messing with the hot glue gun. LOL
There's a little shop near us (a country gift shop type place) that has the most wonderul candles & potpourri! I like to fill baskets in each room with some of it.
Basically, we do everything but the tree ahead of time! Well, except the stockings - they don't get hung until maybe a week before Christmas - just because it drove the kids nuts when they were little & I haven't changed it.
