Our strategy for Season’s Greedings level 1-20 is to lob the Yellow bird nearly straight up, breaking through the snow holding the two stone blocks on the left side. Fire the next Yellow bird low, through the small pig and present, continuing onward to drop the pig on the far right. If the top pig remains, split the Blue bird through the snow blocks supporting it. The score in the video is 49,170.
Note: The video below shows the Santa Hat glitch. This glitch has since been fixed and thus is no longer possible. The trigger was the Santa Hat atop the bottom-left pig. To see which levels have the glitch, we have tagged them.