We can't do good heraldry if we don't know what it looks like. There are rolls of arms out there, but a lot of them are hard to find, and the ones that we can find have a handicap: they're meant for heralds, who can read blazon. They're accurate, and fully documented. That's not what we need.
This is a list of links to rolls of arms. It will bypass the introductions and take you straight to the pictures. Follow these links and you can immerse yourself in the visuals of heraldry. You'll come away with a better sense than you might have had, of what heraldry looks like. And then you can go help people design good heraldry.
Be aware that this is not a substitute for scholarly heraldic resources like the Medieval Heraldry Archive of the College of Saint Gabriel. This is an emotional aid; it's here to help you feel what heraldry should be. Use it and then go looking for the details later.
Similar Collections
An Annotated List of Period Armorials Available Online
English Heraldry
A Caerlaverock Roll of Arms
Arms from the Siege of Caerlaverock
An Elizabethan Armory (click through for Viscounts etc)
From the Bodleian Library and again
The Dering Roll
German Heraldry
More to come...
Non Scripta Non Est