How would one organize an Eevee/Eeveelution collection?

I’m trying to plan out how my hypothetical large Eevee binder would look, and although I don’t want a ton of other language variants, unique non-English cards are on my radar (such as the CN only gem pack eeveelution cards), but then how would the JP stamped promos fit in there? I see a ton of Eevees in the SM era alone from events with unique stamps, do those count? Or should it be unique art only aside from EN cards?
I’m a young adult about to finish college so I can’t exactly spend thousands per month on filling in pricey eeveelution slots in my binders, but looking for a few commons here and there are always fun. Does anyone have advice on where to draw the line as far as what to include? I know just by having Eevee as a favorite, the prices of some cards (umbreons..) are already horrible, but how far “counts” to y’all?
I also really like keeping some promos together, like the BW promos and the Yu Nagaba eevees, but then that opens up the prospects of just keeping every eevee and eeveelution together?

Basically a LOT of overthinking so I don’t move all my cards around just to forget something, if anyone has some ideas!

Still new to collecting Eeveelutions and close to minimum wage I concentrate on the artwork. I collect them all and if another language is cheaper or more easily available I am happy with it. All variants, languages and cameos are welcome, but when I have one specific artwork, the variants become less important. Right now I don’t expect to be able to get all the expensive ones too. I also look out for damaged cards. Better to have an artwork in a poor quality for cheaper then missing out.

EDIT: I don’t do spreadsheets so far. There is no plan what should be next. I hope I can get colour coded binders for each Eeveelution in the future because a single 4x4 binder gets already a bit crowded.

Oh, and…