All else equal, buttermilk will make a fluffier, more delicate pancake. Because it's thicker than milk, so you can get a the same consistency with less flour. But it's not necessary.
I think the basic tricks are
1) make the batter thick enough. It shouldn't flatten out and spread too much when it hits the pan.
2) make sure your leavening is ok. Baking powder expires. It may lose oomph even before it hits the expiry date.
I use about 3g baking powder / 100g flour. That's about 1/2 tsp per cup. This is for non-buttermilk. If the baking powder seems dubious, use more.
Edited to add: another common way to add fluff is to separate half or even all the eggs, and just mix the batter with the yolks. Whip the whites (generally to very soft peaks) and fold them in at the end. I used to do this fairly often but decided it wasn't worth it most of the time. There were easier ways to fluff things up.
