I feel like I need TWO outfits for everyday.
For a 7 night cruise .. My practical advice for men is "shift" your shirts ...
Day 1 (boarding): Shorts 1 and Polo 1 (polo 1 done)
Evening 1: Slacks 1 and Polo 2
Day 2: Shorts 2 and Polo 2 (polo 2 done)
Evening 2: Slacks 2 and Dress Shirt 1 / suit (assuming formal night, along with a coat / tie)
Day 3: Shorts 1 Polo 3 (shorts 1 and polo 3 done)
Evening 3: Slacks 3 and Polo 4
Day 4: Shorts 2 and Polo 4 (shorts 2 and polo 4 done)
Evening 4: Slacks 1 and Polo 5
Day 5: Shorts 3 and polo 5 (polo 5 done)
Evening 5: Slacks 2 and dress shirt 2 and tie (assume semi formal)
Day 6: Shorts 4 and polo 6 (polo 6 done)
Evening 6: Slacks 3 and polo 7
Day 7:
Castaway Cay - so swim suit / tee shirt - maybe short 3 and polo 7 back on board before dinner
Evening 7: Slacks 1 and polo 8
Day 8: (Leave the ship

) Shorts 4 and polo 8
so for 7 nights and "two outfits per day" you have ....
Shorts: 4
Slacks: 3
Polo shirts: 8
Dress Shirts: 2
Tee Shirt: 1 for Castaway Cay, maybe a couple of others for daytime around the pool
Couple of swimsuits
instead of
Shorts: 4 to 8
Slacks: 3 to 7
Daytime Shirts: 7
Nighttime Shirts: 5
Dress Shirts: 2
It does not save a lot, but it saves some.
I understand that this is totally unsatisfactory for the fairer sex, but for most guys it will be adequate

.