I think the thing to decide is what you want your collection to be.
Focused on (for example) a style, a movement type, a make, a material, a complication, a country of origin or a range of uses...
I have decided to go for a range for every occurrence; a dress watch, a daily wearer, a beater, an exercise/activity watch and a couple of sentimental pieces. Any addition to my collection would likely be a GMT, chronograph or moon phase watch.
Focused on (for example) a style, a movement type, a make, a material, a complication, a country of origin or a range of uses...
I have decided to go for a range for every occurrence; a dress watch, a daily wearer, a beater, an exercise/activity watch and a couple of sentimental pieces. Any addition to my collection would likely be a GMT, chronograph or moon phase watch.