Besides the padding, you need something to apply onto your feet
where it get blisters.
There is also a spray that function like a plaster for the
affected area, especially if you already has a blister there.
But it spray like spider web onto the feet, and its very white and
obvious.
Is it a pair of heels or a pair of shoes?
If its heels, no choice has to put on plaster on top of the
blisters. Get those cloth sticky big plaster type.
If its shoe, at least still can put plaster and hide inside the
socks. Just remember to put on some cornstarch powder to keep the
feet dry.