First, grate the cucumber and squeeze out the excess liquid. You can use paper towels but I just like to use a dishcloth and press it very well and then let it sit while I combine the rest of the ingredients. I've even used a very thick regular yogurt and it didn't turn out too watery as I really squeezed the liquid out of the cucumber. If you use greek yogurt and it's too thick feel free to add milk or even a bit of water. Use as much garlic as you like, keep in mind that if you use smaller cloves you'll need more. I like to use a good quality olive oil that gives it's fruity flavor to the tzatziki. Combine all the ingredients together with a spoon and let sit at least 2 hours in the fridge before serving. Before serving have a taste. You may need more salt or if your yogurt isn't super fresh you may need a pinch or two of sugar as yogurt gets more and more sour as it ages and might not taste as good as it should. I served these with Greek burgers, raw veggies or even just with fresh homemade pita bread or pita chips. The pita chips in the picture were made by brushing a few pitas with olive oil and sprinkling with sea salt and then baking in a 375 degree oven for 7-10 minutes, watching carefully so they don't burn. You can also add any herbs or spices you like.