@CapeTownCloudChaser, here are a few of the resources I use for DIY. Perhaps you will find them useful.
The Flavor Bible. I have the softcover book and the ebook. It is the most comprehensive guide that I know of regarding flavor pairings. For example it will tell you all the flavors that are known to work with Strawberry. TFB is extensive in scope. Nearly every time I create a recipe the Flavor Bible sees use. There is likely an online copy to be found on the interwebz.
How to Pair Flavors: A Comprehensive Flavor Pairing Guide A decent web page that has sound pairing information.
FONA International has some excellent information that can be applied to DIY. They are one of the largest flavor companies on the planet. Their Insights section has many useful tidbits. Each insight can be downloaded as a PDF file.
Insights
The Bakers Almanac has an excellent fruit flavor pairing page.
The Ultimate Fruit Flavor Pairing Chart
From the Tasting Table:
How to Pair Flavors Together
From FBN:
Mastering the art of flavor matchmaking
Personally, I view creating good DIY mixes as no different than creating decent dishes in real life. Obviously there are differences between real life pairings versus DIY. It's not always a 1:1. However the science is exactly the same. Some companies in the food and beverage industries are using the same flavors as we are in DIY.