1. don't play the harmonica or mutter wistfully about home (most definitely don't show people the picture of your girl/new born child)
2. If shot but it bounces off your helmet do not then take your helmet of to check, you will be shot in the head again.
3. If someone comes up with a crazy/stupid idea it will work, especially if someone says "its a one in a million chance but it might just work"
4. don't worry about your gun jamming/running out of ammo, this only happens when you opponent also has the same problem
5. All american units will have the following: 1. a hispanic, 2. an irish american, 3. a native american, 4. a mid west farm boy, 5. an itallian american, 6. someone from the bronx (it seems this area of new york supplies the american military with at least 10-20% of their personnel), 7. a southern backwoodsman, 8. an asian, 9. a afro american (note that 3. 8. and 9. it depends on who/when the film was made)
6. All British units will have the following 1. a criminal neredowell who's life changes due to his life in the army, 2. a cockeny generally called ginge, 3. someone who will get a letter telling of woe back home who will escape only to be caught usually at the train station, 4. someone who used to work in the factory where they make the weapons used by the unit, 5. a welshman (called taff), 6. a scottish soldier, 7. possibly an Irish soldier, 8. a harsh Sergeant who in reality likes his men, 9. a plumy officer who thinks his men are jolly good chaps.