Sorry I don't have measurements, I always wing it. Greek yogurt, must be full fat or low-fat, not fat-free. Garlic powder to taste (since you said garlic powder is OK, I prefer the real thing but have done it with powder). A handful of fresh dill, chopped finely. Lemon juice and lemon zest. Salt to taste. Make sure it sits for a while for the flavors to blend. It does not taste nearly as good freshly made as having sat in the fridge for at least a few hours.