A bag of borrowings

UK constitution :

First past the post

The idea of rule of law

Lawmaking procedure

Parliamentary form of government

The institution of the speaker and his or her role

Irish constitution:

Directive principles of state policy

French constitution

Ideals of liberty, equality, and fraternity

US constitution :

Charter of Fundamental Rights

Judicial Review

Independence of Judiciary

Canadian constitution:

Quasi federal form of government with a strong center

The idea of residual powers

Australia:

Idea of concurrent list

Joint sitting of both the houses of parliament

USSR:

Fundamental duties

Germany:

Fundamental rights being suspended during emergency

Japan:

Concept of procedure established by law

South Africa:

Election of members of Rajya sabha

Amendment of the constitution.