This isn't all that surprising because most of the songs we play are usually those that have basic major or minor chords. Sevenths we may run into on occasion and possibly even a major seventh, but by and large our chord selection is fairly bland.
But it's amazing how starting out your song on an unfamiliar chord (or chord progression) then opens your ear up to all sorts of possibilities for melodies.
So this week we want to concentrate on using more elaborate chords. Or, a single more elaborate chord than you may be used to using. It doesn't have to be all that complicated to play. There are all sorts of two chord songs that you can listen to as examples:
"Use Me" (Bill Withers) is E7(#9) (076780) and A7
"I'll Be Around" (Spinners) is Cmaj7 (x32000) and Bm7 (x20202) - and actually it's in Eb so put a capo on the third fret
The first two chords of "Spooky" (Classics IV) are Em7 (022030) and A11 (x02022)
And, of course, you can always go back to "Horse With No Name" - Em and the infamous "Horse Chord" (200200)
You've got carte blanche on the topic of the lyric. My suggestion would be to come up with your chord progression first and then listen to it a lot and hear what the chords themselves might suggest for a topic. And if you find you're not getting anywhere with that, post up your progression and get some thoughts from your compatriots.
As always, I look forward to reading and hearing what you come up with!