My theory may be a little bit rusty, but wave generally requires:
A stable layer low down (i.e. a temperature inversion)
Barrier (mountain range etc.) which protrudes above the inversion.
Ideally a steadily increasing windspeed with altitude above the layer (laminar flow)
Wind direction within 45deg either side of perpendicular to the barrier
The waves set up parallel to the barrier (not perpendicular to the wind) - the inversion allows the wave to 'bounce' back up on the downwind side of the barrier. You'll find wave is extremely smooth. (again, the rotor underneath the wave is not..) They are also geographically static - they do not blow downwind. If there are a series of barriers, like another mountain range 1 wavelength downwind, even relatively small barriers can re-inforce to produce huge wave (NZ being a good example)
So to answer liam548, it all depends - You can however predict from the forecast info. You want to look at a skew-T chart, aka a temperature sounding, and the terrain profile around your area, though they're a bit of a specialist subject.
It would seem to make sense that the fastest way out of sink is to turn downwind, perpendicular to the barrier - go upwind and you have a lower groundspeed, and escape it into the rotor. If you parallel it - good luck!
Of course to have massive sink and turbulence downwind of a ridge does not require wave...