When preparing aqueous solutions of sulfuric acid through dilution of the pure acid, it is well known that we should add acid to water and never the reverse.
To prepare a solution of hydrogen peroxide and sulfuric acid it appears that the standard operating procedure is the opposite: the hydrogen peroxide is added to the acid, and never the reverse.
Given the similarity between water and hydrogen peroxide, this is surprising. Like water, hydrogen peroxide is less dense than sulfuric acid, has a lower boiling point, and a higher volumetric heat capacity. Therefore, all the reasons why adding acid to water is supposed to be safer than adding water to acid would seem to indicate adding acid to hydrogen peroxide.