A lot of the time, I'd draw a circle, but there'd be what I can only assume is one weird line in the loop where it didn't connect. Fixing these wasn't very consistent, either.
It might be that the line was too short and you didn't realize. You can only drawn a very limited length so it's hard to draw a circle unless it's very small. It's better to rely primarily on your other abilities and use drawing more tactically.