  Effective field theories such as Heavy Quark Effective Theory (HQET) and Non
Relativistic Quantum Chromo-(Electro-) dynamics NRQCD (NRQED) are indispensable
tools in controlling the effects of the strong interaction. The increasing
experimental precision requires the knowledge of higher dimensional operators.
We present a general method that allows for an easy construction of HQET or
NRQCD (NRQED) operators that contain two heavy quark or non-relativistic fields
and any number of covariant derivatives. As an application of our method, we
list these terms in the $1/M^4$ NRQCD Lagrangian, where $M$ is the mass of of
the spin-half field.
