Lavender is a classic scent and additive in soap. One of my first batches of soap was lavender. I used a pretty simple 4lbs recipe that had palm oil (wasnt a fan of it didnt reorder it) lard, olive oil and palm kernal oil. Once my soap traced I added in an ounce of bulgarian lavender essential oil and a small handful of lavender buds, I also sprinkled some lavender buds on top. It turned out lightly scented and very pretty and very scrubby. I recommend grinding your lavender buds if you wish to add it to the body of the soap so it wont be so sharp.
Cucumber can add some fantastic label appeal. Itll be up to you and your customers to decide if they find it adds any luxury to the actual soap. The ground cucumber peel gives beautiful green flecks in the soap but they will eventually fade into yellow due to the chloriaphil. It eventually is broken down and the color fades. A smidge of green fd&c dye can cover that yellowing and the ground bits of peel will give a slight scrubbiness to your soap. If you wish to add the actual cucumber just puree it up and add it in as part of your water. If you have 16oz of water in your recipe use 14oz to mix with your lye and at trace add in your 2oz of cucumber. There are also cucumber fragrances available to help scent this cucumber soap. Some that I have worked with accelorate trace. If your fragrance oil is an accelorater be sure to soap at room temperature. Keeping your temps low will help keep it from moving too fast.