Probably too late now. Next year put an old sheet, blanket, or tutu to hide bottom. Actually having a lot of gifts works well to hide the area under the tree.
I use remnant fabric. You can make or purchase a tree skirt.
You can buy or make all kinds of tree skirts, but if you are asking how to cover the trunk, I have a couple of ideas. Living or artificial, the trunk can be covered in plastic or living garlands. Unless you want to draw attention to the trunk, then use a neutral, green and brown garland without bright flowers. If the tree is live, be sure to leave a space where you can water the tree. You can spray the trunk with paint, or with spray snow. You can stack wrapped presents around the bottom of the tree, or set up a toy train, or even a whole miniature village, or obscure the whole area with netting and twinkle lights. And I always spread a bedsheet or a plastic tablecloth under the tree to catch spills, dropped ornaments, sticky candy canes, or anything else, and it makes cleanup much easier. Best wishes, 😊
Hello, a tree skirt is a common way to disguise a stand.
in addition to christmas tree skirts, you can find christmas tree collars, even on places like amazon!