When it is allowed in your jurisdiction it is always good to start the year with a little practice. For most riders its been 6 months since you last swung a leg over and twisted a throttle. A little practice can go a long way to honing your motorcycle skills. Fortunately, there are lots of vacant parking lots due to the current situation. Always make sure your practice area is free of debris.
The first skill to practice is your muscle memory. A slalom circuit is a good start to dust off the old cob webs. Practice your push steering by weaving through real or virtual pylons. At the end circle around and try it the other way.
Figure 8's are a great drill to re-introduce cornering and turning you head into a turn. Start slow and tight reintroducing your slow speed skills. Keep the throttle constant and use your clutch and rear brake to modulate the speed. You can gradually expand your circle, your speed and your lean angle. Again make sure the area is clean and free of debris so you don't lose traction.
Stopping is perhaps the greatest skill a rider can practice. This can be a life saver. If you recall your motorcycle license training you will know that approximately 70% of the stopping power comes from the front brake. Practice the sequence - roll off the throttle, apply the brakes gradually (load the front tire then squeeze harder, harder, harder). If space allows you can gradually reduce the brake pressure to come to a complete stop. Start at 25 kph and gradually increase the speed of the drill.
In addition to your muscle memory how fine tuned is your hazard perception? Are your eyes leading you and scanning for hazards or are they just along for the ride? Your eyes are the windows to your brain. They will identify hazards well in advance and prevent you from panicking. They will also guide you through a corner. They don't just do it naturally unless you practice and train them.
As non-essential riding becomes an allowable activity enjoy a little practice, it really can be fun!