It was much easier than I thought...took a little while, but we did it without any major errors.
We put it between the crib and double bed. I feel like it would have looked better behind the crib, but we are planning to move out the double bed, hopefully when baby is 6ish months (depending how things go). At that time, the crib will go next to or in front of the tree.

I've posted it before, but here is our bedding/crib

and dresser/glider

Re: Our tree decal is up!
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It didn't come together, but I love how close a match it is!
Thanks everyone!
? Kristen & Austin ~ Married 07.04.09 ?
*photo removed*
It definitely helped to watch the video on their website. See if yours has anything about a demo video. If not, I bet you could look it up on youtube, or you can google Simple Shapes decals to find the video that I used (Simple Shapes is the company).
ETA: oops, forgot to quote..this was meant for SarahandBen above.
I saw that someone posted a youtube video last week and I saved that. That will definitely help.
One question: did you adhere the base of the trunk first and then do the branches? Did you overlap the branches on top of the trunk? My branches have curved ends (on the part that attaches to the trunk) and my instructions don't specify what to do for that, but I assume that's what you do. Just wondering if the overlapping is noticeable or not.