I started out collecting teacups many years back and mostly just had some mix and match. Over the years, I have picked up English sets here and there and so I decided to resell my older mix and match items.
I do have a group of newer ones that are lovely but made in China which I save in my basement that are reserved for my personal teas as I would rather not use my precious collectible ones for that time. I think it puts a "friend" in an embarrassing situation if one gets broken by them so I'd rather avoid that.
I stay within certain color themes when I collect cups and saucers but also have seasonal fall and Christmas ones which I keep in the basement during their off season.
I will be constantly refining my collection.