Regarding the connection between Idealism and Phenomenology
The Phenomenology of Mind (sic!) by Hegel is considered to be the climax of German Idealism (and probably idealism as a whole) and uses many phenomenological examples, e.g. in Chapter II "salt" as white, having a cubic shape and tartness (etc.).:
This salt is a simple "here" and is at the same time manifold; it is white and also tart, also cubically shaped, also of particular weight etc.
I think this to be only consequent, as Idealism's main assumption is that it is the human thought/perception that determines all reality that is of philosophical interest (see the SEP article). Therefore, the phenomenology should be one aspect of it.
Locke as an avantgarde thinker consequently intuitivly used empirical examples without methodologically reflecting on this (as far as I know).
Regarding phenomenology as philosophical method (Husserl)
Husserl's phenomenology as philosophical method, if it is allowed to say this, is not "revolutionary" at all. The ideas of intuitive understanding and intellectual intuition have been kantian ideas (§77 Critique of Judgement, here limiting concepts of our own capabilities, i.e. something not achievable for us as humans), that Schelling, Fichte, Hegel and Hölderlin tried to establish as philosophical methods around 1800 already. This is described in Eckart Förster's The 25 Years of Philosophy, chapters 7-9.
He explicitly describes in chapter 7 how two "traditions" evolved after Kant leaving "loose ends" in his philosophy (see Critique of Judgement, §57, Ak. 5:341, where he states that the reason for the unity of reason cannot be found within the bounds of sensuality): One looking for the first principle of philosophy with the help of intellectual intuition (Reinhold and Fichte), the other coming from Jacobi's reception of Spinoza using the idea of an intuitive understanding (Goethe without methodologic reflection, Hegel as culmination, Schelling and Hölderlin somewhere in between).