A common error is banking away from slopes while in straight flight, whether due to anxiety or visual misperceptions. When horizons are low on one side and high on the other, many pilots will inadvertently level their wings with the ‘apparent’ horizon ahead, even far from terrain. In running a ridge approximately perpendicular to strong wind, crab angles may be very pronounced, and the visual effect of ground moving by sideways at close range prompts that same unconscious, continual bank to windward. It might sound absurd but almost everyone does it until they grow accustomed to soaring near mountainous terrain.
Another mistake, costly in areas of limited lift, is flying too far along the hill and out of lift before turning back. That can quickly waste all the height gained on one pass before beginning the next, and when conditions are weak it could even shoot you down. Instead, anticipate where the lift will end, turn back earlier than necessary at first, and then gradually explore further on each pass. This will almost surely help you ride the slope higher, as no precious energy is wasted.