This article was written to for Americans in particular, to offer some things to note before going to Spain. 

What is alright to wear in the office in Phoenix differs from what office wear is in Spain. Polo shirts and chinos are too casual. Wear a dark suit and tie.

Shoes- just a good pair of business leather shoes. No one wears tennis/athletic shoes, unless they are running a marathon or at the gym. 

No tank tops, they are considered very low class. Wear something that covers the shoulders and no shorts- no adult Spanish man would be caught dead in a pair of shorts!

Men wear watches, its a status symbol- but good ones, not cheap plastic. Only children wear plastic jewelry or cheap watches.

Women wear skirts or long pants, young ladies may wear clothes a bit less convervative. Remember that Spain has a large Catholic population, even if you are not religious the attire reflects a conservative style (compared to easy going USA that is).

Women in Spain dress their age, it is unlikely to see a mature Spanish lady wearing spaghetti strap top and miniskirt. Those are for 25 years old or younger.

If you go out in the street in Madrid, you will see what Spanish men wear for casual outdoor night life: Black jacket (leather is perfect) and jeans. This seems to be the "uniform". As of 2014, the women are wearing leggings and a LONG top and scarf to wear around the neck. The women wear tops the cover the "bum area", mind you. 

Women like to wear a loose scarf around their shoulders/neck as it makes her outfit look polished.

The people are "put together": that is, they appear to take care in choosing their entire outfit before even leaving the front door. 

People in Spain do not smile at strangers unlike in the U.S. where you may smile at passersby. They do not do this in Spain, if you smile at someone they may think you have some ulterior motive. It is not necessary to smile and greet total strangers there. This is probably the most difficult thing to un-train an American- to NOT smile at strangers! This does not mean the Spanish are unfriendly whatsoever. It just isn't the way they do things there. Spaniards have respect, to smile at someone you do not know is a bit too familiar. 

The work hours are a bit different there than in USA. While Americans put in 8 or 9 hours and clock out, in Spain they linger at the office and take longer times to do things. In fact, maybe that fact could explain why the Spanish have such late dining hours? 

Spaniards dine LATE: it is not uncommon to see entire families with small children out eating at restaurants even at 11pm. Speaking of dining, there is a lot of pork and ham in Spain. If you don't like it, that's too bad, it's everywhere :). This could be a holdover from the Inquisition, as Jews nor the Islamics could not eat pork products. They also have a lot of seafood on the menus, so if you don't like that either you are duly warned. 

The population is a bit more trim than Americans are- Spaniards are thinner, more in shape. The reason for this may be because:

Spaniards GO OUTSIDE! There seems to be a "community spirit, because when evening comes, the whole town comes alive with people.  They all come out to stroll, shop, eat, or just people watch. They won't be inside playing World of Warcraft, they walk and walk and WALK.  The lovely scenery is conducive to walking, perhaps, as there is so much beautiful architecture, pretty streets to walk upon, and picturesque shopfronts. Why stay indoors when there is so much eye candy to see? Speaking of eye candy: the women there are stunning. Travelers observe: "the women - they all look like Penelope Cruz"! 

Europeans seem to be shorter and thinner than Americans as a whole, however.Especially the ladies, they are just tiny- much thinner, shorter, and with smaller feet than many American girls.

Spanish TV: similar to American sitcoms, they all seemed to be "ripoffs" of American shows. They also have the same type of TV commercials, like for "female" deodorant type products. The BBC msy no longer available on Spanish TV? 

 Many Spaniards still live at home with their parents long into adult age. This is not a bad thing, it is perfectly normal. The pay there is not as great as it is in the USA, not only that, but Spanish men are expected to live at home until they are married, and it is not uncommon for married couples to live with their in-laws or parents. It is actually unusual for a Spanish person to have their own place, male or female.