I recently came across this excellent introduction to using parallel modes to select different chord possibilities in an original chord progression. The production and explanation of the techniques is very well done.
Although it might seem that this technique is primarily geared towards the jazz composer, “classical” composers who want to explore tonal harmonies but move outside common practice harmonic language will find some interesting sounds to explore with this technique. Pop or rock songwriters might find an unexpected chord borrowed from parallel modes a great way to explore a harmonic “hook” in their tune. Improvisers will want to study the basic advice on how to select melody notes over a chord progression like this.
This can also become a standalone composition exercise. Just like performers will practice etudes and other exercises that aren’t intended to be performed for an audience, composers can get a lot of value from doing short composition projects that force you to be creative within the constraints of a box. Try taking a very basic diatonic chord progression of 4-8 measures and reharmonizing it musing modal interchange, then write a melody or improvise over it. Exploring different sounds like this increases your compositional pallet, even if the specific short composition never gets expanded into something you want performed.