Add a small visual cue such as X to make the centre of the virtual playspace
Despite have a fairly large play space, I still find myself drifting towards the edges of the room.
It would be very useful to have a small visual cue (such as a X) marked permenantly on the floor in the middle of my playspace so I know where to stand without raising my headset or seeing the guardian boundaries
Shu Tse commented
Many people put a small rug or carpet in the centre of the playspace so your feet can give you feedback on where you are. It's easy to get used to and keeps you immersed.