I love to make flashcards out of index cards. One way to make them is to put your information on printer labels then put the labels on your cards. But I've found that these cards are just big enough to run through printers and are sturdy enough to handle some wear and tear. And to keep different sets together/separated I use a 3 hole punch to line up the hole and punch a single punch and put it on a ring. (I'm obsessive about things matching and lining up.) I've made them for sight words spelling words addition/subtraction facts. Apparently I'm going to have to make some multiplication ones soon.
I use these cards for business & personal. They are always good for recipes. When starting a new computer program they are always good for making notes about what you might find important. You never know when you might forget a very important detail or something you don't want to repeat. I have also used the cards for flashcards for the kids to use on their homework. I have also noticed some use them for notes when making speeches. One thing about them they are very durable cards. There are so many uses for the cards.
The cards are used for every day note taking and serve it's purpose however I would maybe go for a name brand if I were to use them for a presentation or professional use