1. Create a new document 500 width and 500 height. we will need to create the shape so i would like you to select the Ellipse Tool and then to click on the document don't forget the foreground will be the color for the circular so make sure you've selected a nice christmas color.
And also to create the shape the size you want it click on the drop down arrow on the toolbar when you click on the shapes and you will find this as shown below.
2. Now we need to add some blending options to our circular orb the settings are shown below.
Now for the inner shadow add this following color #D2D1D1 this will create the outburst of light but this will not make to much of a difference.
You can always mess about with the settings to give your christmas orb effect more to your liking.
3. Now you should have something looking like mine below.
4. We need to add a little lump at the top so it can stick on to the tree this is very simple goto filters - and liquify and your done as shown below we have more stuff to do yet don't worry.
5. Now you might want to add a image to this or some simple text like merry christmas but ill do both ill add a image so you can see what it looks like and add some text.
6. You will want to make this blend into the orb as shown below.
We will be able to shape this around the orb and we will be able to get rid of the white and to remove the white is simple the settings are shown below.
Now you should have something like mine below.
Or even add text as shown below.







More Photoshop: