All three words have similar roots, but judicious applies to human character in general. Judicial and juridical are more specifically connected with matters of law.
Judicious means "wise, showing good judgment."
Judicial means "relating to courts of law or judges."
Juridical means, more specifically, "relating to the administration of justice."
Examples: He judiciously invested in mutual funds.
(Showing good judgment)
The case is going to judicial review.
(Review by a court of law)
Some laws make specific juridical requirements for sentencing.
(Requirements for administering or dispensing justice)