Today we're learning a strum pattern that incorporates some root note picking, some upstrokes, and a nice thunk on the guitar body.
The first time I tried to intentionally whack my guitar during a strum pattern, it felt horribly awkward. It took me a while of slow, intentional practice to get a bit of a flow happening, and then over time it has simply become a natural thing that happens as part of my style.
So we're starting off with the root note, then a strum, then that whack.
I use the tips of my fingers, in a convenient area of the guitar body. If you experiment with it, you'll find acoustic guitars are tremendously, well, acoustic! They're like drums, and if you hit them in different ways in different places, you do get different results. That said, your hand has to actually travel that distance during the strum pattern, so realistically speaking you might not have too many options. It depends on how fast you're playing I guess.
Then we're also playing the upstrokes, which produces a bit of an offbeat feel.