Above or to the side of the line, air is relatively smooth and upflowing – below, it is downflowing. It steepens as wind velocity increases (and the severity of the slope), as does the area of downflow, and moves toward the top of the hill. One tip: you don't have to keep the whole helicopter one side or the other— many pilots work the line by keeping only the blades on one side of it. The fuselage by itself is not affected much by turbulence. However, this is a lot of work, and an easier method is to make sure you can see down the windward slope, and approach at 45° to get a safer angle.
Having decided on wind direction in general, you now need to look more closely at your proposed landing site. In strong wind conditions, you won't need the contour crawl at all, because it's obvious where the main body of wind is coming from, but it may have very little influence over your final approach anyway.
The basic manoeuvre is a figure-of-eight type inspection, making all turns away from rising ground (returning towards the site) to give you a good view all the time. You could go round in a circle, but the landing point would be out of sight most of the time.

As with any other potentially dodgy landing site, you need to check for Size, Shape, Surroundings, Slope, Surface and Sun (you don’t want it in your eyes). The most important, however, in this case, is Slope, as there's no point trying at all if you can't land. You will get little idea of ground conditions if you overfly the site, so what you must do is have a look at eye-level, which results in the aptly named Eye-Level Pass (if the site isn't surrounded by trees).

The most economical way is to start with a downwind pass, turn round and land, which is entirely possible if you know the wind direction before you start. Sometimes, though, this is not obvious at all, so just make an educated guess and fly at about 40 kts in the direction you think is downwind very close to the site, level with your eyes. This point is crucial. As you do so, note the reading on the altimeter (those people used to QFE may want to set it to zero), and climb up an extra hundred feet as you increase speed to about 60 knots, using the collective.