After a bit of practice, Sebastian has mastered the art of crawling forwards! The past couple of weeks he has been working hard at it, and for a bit could only manage to go backwards which resulted in not quite getting where he wanted to go as well as a few awkward predicaments.
From that he decided it was more effective to alternate between sitting and transitioning to his belly over and over again. This eventually got him to his intended destination, but it took a while.
Thursday, however, when I got home from an errand and walked into the room, he crawled forward to greet me. While still not speedy, he can now take a direct path to wherever he wants to go–usually to eat the crumbs from under the table or the bits of paper that end up in the floor.