When I started mixing I tried to estimate flavoring % based on others' recipes, and it worked okay but it still felt a little like shots in the dark. It wasn't until I started testing my flavors individually that my eyes were fully opened to the intricacies of the flavors and what %'s to use. I created 4ml samples of each flavor, in my usual 70vg/30pg 3mg/ml base. I mix the flavoring close to the mean or median % I found on the flavoring listing here on ELR, shake and vape it, and record my thoughts on it. Then wait a week or two and vape it again, making notes if the flavor changed after steeping. I highly recommend testing all of your flavors and making extensive notes on them.
I also recommend starting by inventing 2-3 flavoring recipes, your first recipe has 7 flavors in it at pretty equal percentages so it's going to be hard for you to learn much about the flavors and know what to adjust if it doesn't taste right.