Probably THE most helpful item in my learning has been the database for The Good Scents Company. Commonly called TGSC.
Mark Evans from Australia put up a searching website for perfumers that between TGSC and Mark's Site, I use maybe 25 times a day.
For each element that you seek, there is an Organoleptics portion for each element that tells relative strength, for which you can gauge by this man's judgement just how strong, in a general sense, how strong something is.
Still, the best thing, is your own nose and experience, that is only gained by work.
If you don't want to become a Perfumer, then don't put in the work. But, if you want to progress and grow then the work of learning your materials is perhaps THE most important thing to learn. This allows you to be the best at what you like, the blending... because *then*you will know how, what, and why to use something.
Tedium is a part of the learning process. Repetition is a part of the learning process.
But still, relative strength is also relevant to what you pair the element with... And this comes from experience and experimentation.