@Mistress_Of_Herbs & @Ostara the only reason the Elderberry Syrup is so âthoughtâ out is that itâs from Tamed Wild Recipe Book. I didnât come up with that one on my own 
My husband plays guinea pig for me too sometimes my daughter depending on what it is Iâm doing. Usually, I have a bad habit of doing things as they feel right & then totally forgetting to record or make notes or write it down⊠so nothing is ever done twice the same way⊠or at least not exactly the same.
The roller bottles for Chakras required me to figure out how many âdropsâ to carrier oil I needed for a 10ml bottle. Thank goodness for online conversion calculators 
For my diffusers, I usually do 10 drops per oil for every 100 ml of water. If Iâm using multiple then I will break it down by the recipe on hand or how strong the oils are by themselves. My diffusers are between 250 & somewhere near 500 ml (the smaller of the diffusers is in my bedroom). Then if it needs to be stronger then I add 3 drops per oil at a time depending on which ones are lacking. I kind of bounce between actual recipes & tweaking them or other directions for things to how it feels right to me.
I love the Florida Water diffuser blend we have: What is Florida Water and Why Do We Want It? 
there are actually multiple ways to make the water within this post. I like to make it fresh with vodka & I like the diffuser blend for overall good vibes in my room or houseâŠsometimes both diffusers have the same recipes sometimes I do them differently for each room.