To fluff an artificial Christmas tree, first, remove any ornaments and decorations from the tree. Then, begin by fluffing the branches one by one. Start at the top and work your way down, pulling each branch out and pushing it back in to create a full, fluffy look. Be sure to pay extra attention to the outer branches, as they tend to be the most visible and need the most attention. Finally, if your tree has any plastic or wire supports, make sure to adjust them to support the branches and give them the proper shape.