OP, I am going through something similar and it is really easy to get off track.
(I built a fine jewelry collection a while ago, got bored with it, and now I'm into chunkier and casual pieces which have their own issues since I am now trying to avoid plated and expensive. Today I discovered some Bony Levy pieces I loved, but they don't go with much that I have so I would need to start another collection of "delicate" jewelry.

OFF TRACK!)
Anyway, here is what I suggest:
Every time you see something online that you might like, download a pic to your tablet or phone and organize these pics into albums. (I use the Photo Manager Pro app because it lets me organize albums hierarchically.)
Then start putting collections together of items that you would wear together. You may not have a good idea of the proportions, but at least you could see what styles go together. You can even bring bags and clothes into the collections if that works. (I use the pic stitch app to combine pics of items.)
I am always adding and deleting items from my wish list photo album, and combining different items using pic stitch. For example, does this watch look good with that bracelet? Does this pendant work with those earrings?
Obviously if you get the standard pieces in a single metal with mainstream styles, they will probably go together. But if you are looking for signature pieces, it becomes more difficult. If you are used to wearing bold jewelry, I have a feeling you might enjoy signature pieces more. You just have to find the right ones.
Look at your wish list photo album often and find new things to add. Delete the ones you get tired of looking at. After a few weeks or months, some pieces will have stayed for a long time and you may know for sure that they are "you". (Some of them may have gone to outlet or clearance by then!)
FWIW, you should be able to find standard pieces very inexpensively: gold bead stud earrings, pearl stud earrings, wire hoops, pearl pendant or choker, cz pendant. They will last just as long as more expensive pieces. I would save your money for the signature pieces you fall in love with.
BTW, my favorite pieces at this time are from Elsa Peretti Tiffany (no purchases yet), Bony Levy (no purchases yet), Movado watches, John Atencio, Na Hoku and Kabana, Ippolita. My styles are modern, smooth and flowy, slightly edgy, or casual and beachy.

(Not traditional or sparkly.

)