How do you build your collection?

[Cimballi]

First, let me say that I clearly understand that purchasing a watch can be driven by a combination of logic and emotion.

Second, from my humble point of view, a watch collection is defined by a logic.
In absence of logic, it is what I would call "an accumulation of watches", which could be an awesome one, BTW.

From the beginning, I tried to set a logic and a target number for the watches I purchase.

Here are a few examples of numbers/logics in a collection:

One watch: engagement present
Two watches: weekdays/ weekend
Three watches: work/home/sports
Four watches: steel work/ gold work/ sports beater/ formal gold
And so on...

You can base your logic on so many parameters: usage, metal, complication, provenance, brand, age, movement, color,...

After much thinking, I ended up with a target of 10 watches and a logic based on dress style and usage:

SS diver,
SS chronograph,
SS pilot,
YG dress,
SS dress with silver or white dial,
SS dress with blue dial,
SS or titanium beater,
Plastic quartz sports,
SS GMT,
Vintage from my birth year (my wild card)

What is your logic for building your collection?