If you are a bit like me, and do everything in the last possible moment, you might find yourself stranded with a Christmas tree, but without a way to make it stand up. :/ Here's an idea I came upon, to use what I have at home to make a simple reusable Christmas tree stand out of cheap IKEA stool.
You don't have to sacrifice the stool, as after holidays, you can simply remove the legs from the tree and re-assemble the stool, waiting for the next Christmas.
Step 1: The Stool
The stool in question is very common Frosta wooden stool from IKEA, costs about 10€. It's made from plywood and the legs themselves are super sturdy.
Just dismount three legs by unscrewing the screws. Depending on the thickness of your Christmas tree, you probably don't want to reuse the same screws for the tree, as they are a bit too short. I was using 5cm screws instead.
NOTE: You might even try using all 4 legs, but I found it would be hard to fit all four around the tree, and it's a bit of overkill, as three are perfectly enough.
Step 2: Mount the Legs to the Tree
If the tree bottom is too uneven, you might want to straighten it a bit first, to get the stool legs as close to the surface as possible. Use a small axe, or a saw.
Then screw the stool legs to the tree. At best, have someone help you and hold the tree upright, so that you get all three legs straight. I didn't do it for the first two legs, so I got it a bit uneven, but it doesn't really matter that much. You can adjust the angle of the legs by tightening and releasing the top or the bottom screw. You want to get the horizontal part as even to the ground as possible.
Step 3: Decorate the Tree...
...and have a merry Christmas!