Be as careful as possible. Look out for everything and don't trust any driver. Even if you have eye contact, it doesn't mean a thing here. Assume they don't see you. I was hit this past November by a motorbike in an intersection, they're everywhere, especially on the sidewalks.
I ride often but not everyday now that it's cold. I stick to a combination of roads and sidewalks but you can never be too careful here. I rode for a year in a rural area and that was better but now that I'm in Seoul it feels like a battle every time I ride.
Be safe, ride on~!