Your fastest way to farm any Artifact Spot drop is to use Treasure Totems at the Beach. I'd do this and replay days if you don't get many as I was testing this strategy out for some other uses. I'll see if I can dig up (lol) my old posts as I included my drop rates on various attempts.
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Here you go:
Winter 21 is Groundhog Day, also known as RNG Day
Quick summary of dolls when blanketing the Pelican Town Beach in Winter (a BAD idea as Winter adds in more drops) with Artifact Spots, each is a different try:
0, 4, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1
Yikes that's terrible, but there was 1 good day!
I would not blanket The Beach with Totems as that's
terribly wasteful for a limited resource, instead look to make an optimal coverage setup in Stardew Planner to get the most tiles per Totem with fewest overlaps and follow that pattern. I did this with the Ginger Island Beach to get excellent efficiency in coverage with 14-17 Totems but I don't think I mapped that out for the Pelican Town Beach yet.
By the way, my continued Stardew Year 6 existence is mostly geared towards farming the necessary items to make Treasure Totems so this is my jam!