Because, why not?
All you need is:
A big ol' book or three
I used leaves from my crazy big lemon basil plants (leaf confetti is awesome, but leaf confetti that smells delicious? come on now.), tomato plants, and whatever other plants had nicely size or colored leaves.
I chose a big, thick book for drying (one that I wasn't worried about getting slightly stained or warped from the moisture in the leaves) and laid the leaves out on various pages, making sure the leaves didn't overlap each other. I stacked some other hefty books on top of the leaf-filled one for extra smushing power.
After two weeks, your leaves should be dry enough to work with. It depends on the thickness of the particular leaf, of course, but, in general, two weeks should do it. The leaves should feel fairly stiff and, well, dry! If they feel cool to the touch and/or are still pretty flimsy, leave them to dry a little longer.
A hole punch with a little catch tray is best. The confetti pieces collect in the catch tray and you can empty it into a container as necessary. You may not be able to get the hole punch to reach to the middle of the leaf, but that's okay - if you're really dedicated you can punch the edges of the leaf first, then snip the leftover bits away in order to reach the middle (and make some awesome confetti bits using the mid-rib!). I usually don't bother with that, but instead dry a combination of larger and smaller leaves so I have options.
That's it! It's really simple, and really satisfying. You can do with this confetti just about anything you'd do with 'regular' confetti - dress up the tables at your friend's baby shower, glue them to a homemade greeting card, use them as part of your photo staging when taking pics of your own handmade work - or just put them in a bowl and ogle/fondle them (currently what I am doing). If you're feeling extra ambitious, dry some flower petals, too, and add them to the confetti mix (leave them whole - flower petals are too delicate to be confetti-ed!). The mixture of shapes and colors is really lovely.