Line a mesh strainer with a few layers of cheesecloth or food-grade muslin (called étamine in France). Set the strainer over a deep bowl and scrape the yogurt into the cheesecloth-lined strainer. Fold the cheesecloth over the cheese, set a small plate on it with something not too heavy, such as a 14oz/400g tin of tomatoes, and refrigerate for 2 days.
Prepare any seasonings that you wish to use (if you want to roll them in something) and spread them on dinner plates. Pour the oil into a clean 1-quart (or larger) jar.
Use a spoon to scoop out labneh into rough 1-inch (2,5cm) rounds. Use your hands to roll them into smooth balls and drop them into whatever seasonings you want to roll them in, if using, then roll them around to coat them. (If keeping them plain, just drop them into the oil with any seasonings added, being careful to avoid letting them slide down the sides of the jar.)
If you wish, add a few branches of fresh herbs, some chile flakes perhaps, and additional olive oil if the labneh balls aren't completely covered in oil. Cover with the lid and refrigerate until ready to serve.