3 parts HCl (hydrochloric acid) to 1 part HNO3 (nitric acid)
Mix aqua regia under a fume hood since the reaction of HCl and HNO3 produces NOCl (nitrosyl chloride), Cl2 (chlorine gas), and H2O (water) .
5 parts H2SO4 (sulfuric acid) to 1 part H2O2 (hydrogen peroxide)
Add the peroxide to the acid, not the other way around. The reaction to produce piranha solution evolves heat, possibly boiling when the reactants are mixed.