How to do SC runs in early game?

I just saw a min-max guide suggesting unlocking the desert as early as spring 15 (salmonberry season). They do SC runs this early in game to make iridium bars and sell them. However, my personal experience is that I barely have any resources to make bombs, staircases, or even food (this can be solved by salmonberries). Entering the SC without these essential resources is basically a waste of time. Does anyone know how you can be prepared for SC in the very early game phase? I'm especially curious about the method of getting lots of bombs. Thanks!