Store-bought croutons can be filled with scary ingredients like high-fructose corn syrup, hydrogenated oils, MSG, artificial flavors, and even icky preservatives. Moreover, lots of the croutons sitting around on your grocery store shelves are completely un-vegan-friendly.
The exact measurements are much less important than you'd think here. In fact, playing with the spice:oil ratio will ultimately lead you to the best croutons to suit your specific tastes.
First: Gather up your ingredients. You'll need some bread, obviously. Go with something you like, whether it's day-old French bread, a hamburger bun, whole wheat sandwich bread, whatever. Olive oil (or melted vegan butter) and dried spices are also required.
Let your imagination run wild when it comes to spices - I'm addicted to Bragg's Organic Sprinkle, but I always add extra garlic and onion powder, basil, paprika, and red pepper flakes to the mix. A dash of cayenne pepper is quite good, too.
Second: Slice your bread. This is where the manual labor aspect of crouton-making really comes alive, but don't let that scare you! It's quite a bit easier if you use a serrated bread knife and/or fresh bread (instead of the stale stuff).
Fourth: Grab a rimmed-baking sheet (or two!) and line it with parchment paper. Pour your croutons onto the pan and arrange them in an even layer.
Store in a sealable bag or covered container, almost indefinitely. Use in salads, soups, or even for snacking...