Prep the cucumbers: peel them, halve them lengthwise, and remove the seeds. Slice them very thinly, mix with the salt, and let them stand in a strainer 10-15 minutes. This pulls out liquid and bitterness from the cukes.
Meanwhile, in a medium bowl, mix the yogurt, garlic, lemon juice, and dill. Stir in the oil in a thin stream, and incorporate it well.
After 15 min, rinse the cucumber slices in cold water, then spread them out on a clean kitchen towel, and roll in the towel to dry. Now add them to the bowl with the yogurt mixture, and serve.
Drizzle with a bit of olive oil, if you like.
About the yogurt: if you only have regular yogurt, drain it to make it thicker: let it stand 15-20 min in a cheesecloth-lined strainer, then use as in this recipe.