Post anything gifs/webms/or images that make you rage personally, or those that you believe would make for good redpill material for normies.
One of the greatest ways to redpill others is to just show them the truth of what leftists advocate for, through images and videos of their raw actions and policies. Of course everyone is different so some images may affect some more than others, and in different ways, but generally, when you get it right, the image causes them to recoil as they see the repugnant truth behind what they either believed in or had simply ignored. Feelings of disgust, shame, and finally anger will overtake them, and as they realize they had been fooled, they will be more willing to listen and accept the other side.