In a small bowl, combine the yogurt, dill, garlic, lemon, and salt. Mix to combine. Season to taste with additional lemon, salt, or dill as desired. Cover and chill in the refrigerator until ready to serve.
Trim the ends off of the cucumber. Cut into approximately 1/4" slices. The exact size of the cucumber will determine how many slices you get. One 8" cucumber will yield approximately 30 slices.
When ready to serve, lay out the cucumber slices on a cutting board or platter.
Place the yogurt mixture in a ziploc bag and cut off a bottom corner for an opening that is approximately 1/4" wide (you can also use a pastry bag for this).
Squeeze the yogurt mixture on each cucumber slice as if you are frosting a cupcake. The yogurt mixture will be a little thin and more likely to drip. You can turn your bag upside down to help prevent dripping between each slice.
After the yogurt is on each cucumber, garnish with slices of cherry tomatoes, kalamata olives, or feta cheese as desired. Serve chilled.
Notes
Getting through a bunch of a fresh herb can be difficult, so I like to use the tubes of fresh herbs that you can find in the herb section of a grocery store. You can also substitute for dry dill, just reduce to 1/2 tsp.