The idea of a rest frame for a point particle is most useful when it is defined as a proper‐time‐dependent basis of the Minkowski vector space with time axis along the tangent vector to the particle’s worldline. There are many such rest frames; the different possibilities rotate with respect to each other. Methods are developed to make simple and workable the concepts and techniques to deal with the relative rotations. The Thomas precession becomes clear and easy to calculate. Applications are made to spin equations.