The branches are stamped with my old favourite "Lovely as a tree" stampset.
And the centres of the baubles are stamped with the "Artistic Etchings" medallion.
I have used a clear window sheet, with three circles punched out, to mask the card while I sponged and stamped the Christmas baubles on to the tree.
And then I changed the tree branches to swirly patterns with the Creative Elements stampset.
You can stamp the baubles in different colours and with different patterns and stamps.
To give them that 3D appearance.