To display Christmas ornaments without a tree, consider using alternative methods such as hanging them from hooks on the wall, placing them on mantels or shelves, or suspending them from ceiling hooks. You could also create a decorative display by placing the ornaments in glass jars or bowls, or even creating a miniature village with the ornaments as the buildings. Additionally, consider using a wreath as a base for your ornaments, adding a festive touch without a traditional tree.