I made hundreds of cards to get me through the ACR core exam, and I'll be teaching my kids to make cards when it's time for them to do intensive memorization. Paper is just fine, but I think this is a situation where digital is better.

Seconded here. So far only used ready made sets, especially the fantastic CCNA one from Jeremy's IT Labs. But I guess that if I fix few more errors, I'll break into creating my own cards.