I used to play face to face fairly frequently, less so now. Getting newer players to write orders in the traditional "A Par-Bur" and "A Mar S Par-Bur" can be very challenging (I can't tell you how many times players mistake the second order as being sufficient for the entire move) but as the person reading the orders you need to be very leniant.
I find it helpful to set two alarms in order to encourage a proper timing to orders; the first marks the end of negotiations and the second, a minute later, marks the time where orders are due. Everyone is still late anyway, but less so this way. When it comes to blatant mistakes, due to forgetfulness or ignorance of the rules, I have grown accustomed to the "one do-over per game" rule.
Face to face negotiations are the most fun part because there is no order to them. It helps to have several rooms available (or one very large room) in order to give a false sense of privacy, because the only thing that should be sacred in a face-to-face game are submitted orders. Anything else is free reign for espionage and deceit. It is immensely helpful to have multiple copies of the board or at least the map available to players. Sometimes this means an extra board set up in a side room that is updated with the main game so that players can see the pieces as they negotiate, but lately I've been using the free Java program Realpolitik on laptops for people to look at, even going so far as to use the projector that happened to be in the room we were playing in. The downside of this is that if you screw up something on one of the extra boards, it can cause havoc on the main board when people write orders for nonexistent units, so extra care must be taken. At the very least, newer players need to be able to see the map and what areas connect to where, which is why it is fortunate that the newest edition comes with a pad of blank maps.
I can't tell if I prefer FtF games or internet games more because they each have their own special aspects to them. FtF turns into a very social experience with pizza, soda, and chips, while internet games are much more pure strategy. By the way, builds and retreats are indeed supposed to be done without negotiation.
P.S. - If you find yourself significantly short of players (five or less) and want to play anyway, an interesting variant that was surprisingly satisfying is to have each player pick two centers to start units in (doing a rebounding order, so 1-2-3-3-2-1). Builds can be placed in any controlled center, but it creates an entirely new dynamic to the classic game and tends to be significantly shorter because of fewer players.
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