Key modulations

[GeckoYamori]

This is something I just recently started to seriously think about and incorporate into my writing, aside from the basic concept of just switching the key while remaining in the same scale which isn't anything outlandish. I found out that going from a minor key to major one semi note up generally has a nice effect (as does vice versa from major to minor one semi note down).
I figure there has to be several "templates" out there that are generally regarded as pleasant and documented, just like chord progressions. If you could list some examples, preferably with a song example for context, I'd appreciate it.

[JumpingJackFlash]

I found out that going from a minor key to major one semi note up generally has a nice effect

Try using the German Sixth as a chromatic pivot chord, becoming the dominant seventh of the new key.

As an example, assume you're in A minor. The German 6th is F-A-C-D#. (could also be spelt F-A-B#-D#)

Which you then treat as V7 in Bb major: F-A-C-Eb. (Notice the enharmonic change from D# to Eb).

I recommend approaching this chord from the tonic, submediant, or first inversion subdominant chords (in the first key).
Follow it as you would any V7, typically with the tonic (in the new key), with the seventh falling.
(Also be careful how you approach the upper note (D#/Eb in the above example) - avoid awkward intervals and so forth).


The following might also be of some use:
An introduction to modulation (changing key)