First I tried making the slots by hand, which turned out quite messy. However this was useful is guessing the rough sizes of the slots to be created.
Next, I tried different ways to display. A flat circle holder that would display the plants very clearly and rack style made with bamboo sticks that would hold resins at an angle. The circle would not hold more than 6 resins in the box, hence I decided to go with an angled style holder.