Tilt your shoulders at address to align with the sloping lie. This will give you a flat lie. The reason this shot often gives difficulty to a player is that most golfers keep their shoulders level and then swing as they would for a normal lie. Align your shoulders with the slope and avoid swaying by restricting your body action on the backswing a little.

Use more arm swing and less hip movement. The ball will fly higher and consequently you will get less distance, so select a club to give you the required distance. On a downhill lie the same applies but put more weight on your back foot. The ball will fly lower and further than usual so again adjust to choose the right club.