>>331927781
by constantlyplaying.

Start with sessions of 30 minutes or so.
It is important to stay hydrated and to stop imidiatly when you feel the motion sickness coming. If you try to force yourself through this, you might end up associating VR with getting sick (even if it is only on a subconcious level).
Sooner or later you will find that you can go longer and longer, with more and more movement, instead of blinking somewhere.