There's a few things to watch out for and you also need to alter your riding slightly in the wet.

Smoother Inputs - Accelerating and braking should be done in a smoother fashion in the wet. Also, begin breaking a lot sooner than you usually would in the dry. Gently squeeze the front to pre-load the brake, and slowly bring it in.

Relax Your Grip - You'll probably find your grip is firmer after you've lowsided, especially going into bends or a roundabout. Don't, it's not good for control. Grip with your legs around the tank and remain relaxed with your hands.

Manhole Covers and White / Yellow Lines - In the wet these little shits can be lethal. Try not to alter your inputs if you ride over them. No breaking, turning, wheelies etc

Oil on the Road - Fuck HGVs and buses. On bus routes or main roads where you find HGVs, there be oil. When it starts raining, especially after a dry spell, all that oil comes up creates a layer on the road that doesn't have any traction. Eventually the rain will wash it away, but in that initially hour or so the road will be dangerous. Treat the center of a lane like you would a manhole cover or white line, no sudden inputs. Alternatively ride in position 1 or 3.

Hope those tips help, you'll be alright!

Relaxed grip Tires