If you're struggling with perspective in your drawings or comic book panels, make sure to check out Carapace, free art tool released by Epic Games.
It's a simple program (win only) that allows you to place vanishing points around an image placeholder to flesh out the shell of your drawing.
You can also determine the perspective of existing images (handy!):
Looks yummy huh?
For more info see: Free Art Tool Released Thanks to Epic Friday