Besides tax harvesting (selling holdings at losses and switching to a similar index fund), why not move into a fund with big negative capital gains exposure? From Morningstar:
Today, most stock funds in the Morningstar 500 have negative potential capital gains exposure of between 10% and 50%, but there are some good ones with even more. The highest of all is
Fidelity Electronics (FSELX), with a negative PCGE of 509%.
The other idea would be swapping into CEFs trading a big discounts. CEF discount sorter here.