If you collect coins and want to be know as a numismatist please use the correct terminology. 1. The US does NOT strike pennies. Those coins are ONE CENT pieces (see the reverse). 2. The correct term is "Doubled Die", not "Double Die". 3. To be a "cud" the blob on a coin has to involve the rim. I sometimes get sloppy with my terminology but I make an effort to correct that immediately. There must be more to add to this list. Have at it.
I call a dollar a buck and a cent a penny. I call my wife, honey, but that isn't the name on her license. Common things that I often here from collectors that I don't totally agree with include: (1) Buy the book before the coin. I'm crediting this one to the guy who writes the coin books. It seems like a good thing but I forgot much of what I read so it doesn't really help. I learn quicker from seeing, touching, oogling, and sometimes drooling. (2) Buy the rarest coin in the set first. What drug was this person taking? Obviously, the expensive ones. (3) Buy the best quality coin that you can afford. Why would I do that if I could buy two others for the same price with slightly less quality? The author must have owned a coin store with too much non moving inventory.
I collect pennies, mine have a face value of one cent. I don't collect nickels, dimes, quarters, or halfs, they also have a face value that you didn't include on your list. I like the word penny mainly because some of us can't resist correcting me but ignore the other names used for coins of other denominations. Now where is that tongue-in-cheek smiley................
The most common mistake that the average collector makes is they don't know what they think they know.
The beauty of reference books is that they can be referred to. There are always arguable exceptions, but overall I've found buying the best one can afford to be sound general advice, especially for when the time comes for a collector to sell. Agreed.
This could be a bit more obscure but I've noticed that people often get overstrike and overdate confused big time.
The biggest problem with terminology is that too many people use or assign their own definitions to words instead of using the actual established definition.
I guess every in group has their own lexicon to help distinguish themselves. I know number three bugs a lot of people, but I know some first rate numismatists, as in wrote the standard reference book on it, that use 'cud' when it does not include the rim. Whatever, not paying attention to condition and originality are far more common, and costly, mistakes that most beginner make and ones worth pointing out.
When removing staples from holders: 1) point the knife outwards and away from the coin and body parts your fond of. 2) It's just a staple; use a small knife. 3) It's just a staple; use minimal force.