This is just a question I had while chatting with some fellow cardsmiths on various designs, some of mine and some of other smiths. Basically does anybody test their cards while they're designing them and tweak accordingly or, like me, do most people design in a vacuum? I tend to try and find synonyms on Gatherer and do my best to work out where the balance should be but, as everyone knows, I can be wildly off the mark in both directions, UP or OP. (All hail the edit function)
What are your thoughts about designing in a vacuum? Linked to that, how about giving advice and feedback to other people in a vacuum, so to speak.
I'm not sure if this has already been discussed (it probably has) but I was just curious about your thoughts on whether you playtest, to what extent and how you go about trying to theoretically balance a card both when designing your own and trying to help other people.