To make shoes smaller for my summer sandals, flats or pumps, ball of foot cushions are the most practical insole type.
I found these nifty heel liner-meets-insole that will help make shoes even smaller in & around the back of the shoe!
You can add easily add toe inserts for shoes that are too big to act as shoe filler.
You can either wear your everyday socks or, if you'd rather your socks not peek out from your shoes, then footies are your best option.