If wearing new untested shoes...remember that just walking for an hour or two at home...doesn't tell you anything...
Walking for eight or ten hours on the road...is the real test...
Some "hot spots" don't show up right away...it may take hours or days to know if your footwear is any good... Sometimes its the second day that brings out the hot spots...
I carry some band aids, moleskin...and small but sharp sissors...(in check baggage)...
I have cut holes in shoes to relieve pressure points after many days or week of walking... Some shoes will have hidden structural defects that only are noticed after days of walking...
If you get a blister try not to break it open...and switch to open style shoes immediately...shorter days and rest may be the only answer...
As a fall back... a pair of flip flops used for the dodgy showers...could be used as daytime footwear to relieve the pressure points...
Blisters are trip killers...Happiness is getting through the 5th day of walking with "tired" ... but not blistered feet...