Also, toast the nori sheets over open flame. Wave them back and forth over the open flame to lightly toast them, maybe 20-25 times back and forth per sheet.
I also love putting umeboshi hijiki salad in mine but the hijiki comes from Japan so I only have it when I bring it back or someone brings it to me.
And don’t skimp on the SPAM, I like nice thick slices of SPAM in my musubi. Get a nice crispy crust on the outside of the SPAM slices, then glaze and let cool.
I think al ingredients should be room temp, so a little logistical coordination is involved, especially for the rice to cool down. But if the rice sits too long, it may get dry. Let the rice cool and then cover with plastic wrap. Should be good for 10-12 hours.
Also, have a bowl of water handy to wet your hands and clean your press (if using plastic).
Make some extra SPAM so you can snack on mini SPAM rice balls while making them. 