Switch to brush tool, set brush size to 1-2 pixels, set color to white, and on bottom of path palette, click Stroke button. The white line should appear (if it is not strong enough, click Stroke button again).

Christmas Night - making of - Step 33

Using same steps, draw as many lines as you like (remember to delete a path as soon as you clicked "stroke" button). Then, set layer blend mode to "overlay".

Christmas Night - making of - Step 34

We're almost done! Using font of your choice, write your messages. Move and rotate so that the messages align with the lines.

Christmas Night - making of - Step 35

Voila! :-)

Christmas Night - making of - Step 36
   

The last secret is how to create a fish that sends its congratulations too. Using Shape tool (U), draw a circle. Switch to path selection tool (A).


Christmas Night - making of - Step 37

select path, copy-paste (Ctrl-C, Ctrl-V), resize (Ctrl-T, then hold Shift to preserve proportions), then change shape mode to Substract.

Christmas Night - making of - Step 38

copy and paste the circle again, move a bit to top, change shape mode to intersect.

Christmas Night - making of - Step 39

click "combine" button to merge shapes into one shape, copy-paste it, flip vertically, move down to create fish body, then select all shapes, copy-paste, move to the right to create fish tail...