While the old British sailing terminology is lovely to use and "proves" that one is a true old salt the new recruits I take sailing say "huh!!??". "Keel haul the scurvy dogs" is a favorite of mine.
I found though when racing left, right, back front, foresail left rope, foresail right rope worked much better for the new crew than port, starboard, aft, for'd, starboard jib sheet and port jib sheet. ie the crew didn't need extra training in our sail speak.
Should we push our old British (mostly I think) terminology and teach new crew that? Or allow more practical terminology? What do others do on-board?
Not sure why you think the British are responsible for it all. But I think the use of the terminology enhances the experience. And it certainly provides a standard for when crewing on different boat/skippers.
If you use it all the time, you pick it up pretty quickly and it sure sounds better at the bar with a few beers/rums under the belt. (or should I say, 3 sheets to the wind) 
I always call distance in cables, depth in fathoms, larboard instead of port and when I call hard to starboard, I mean turn to port, sorry larboard.
My favourites are "make and mends" and "splice the mainbrace". Banyans are good too.
Sure, when we're sailing on the Palm Beach Bus running a shy three daughters and it's getting a bit snouty because of incoming bits of kingers, we do sometimes tell pit to wake up the boys from adventureland (without moving from BMAX) and get ready for a pole-end peel from the fraccy or a mexican and then an outside to a Code Zero if we can get the upf*&^%er and the downf&^%er going without a wineglass. But hey, at least it's not IOR old school stuff, where you had gollywobblers, blades, tallboys, shooters, Wai Aniwa staysails and bloopers and Golden Dazy gybes to worry about when you were trying to keep a pintail under a flanker.
I dunno, how can anyone find that sort of plain English confusing? 
It's not like windsurfing, where you have to learn how to do an endo willyskipper flaka to be one of the in crowd.
For good clean fun, you can also explain to the kids how you own a boat that weighs 2.1 tons and is one of the lightest half tonners ever made. Or how you used to sail on 30 foot long Etchells 22s and own a 20 foot long Flying 15.
It's an old tradition of the sea, after all. It's like in the navy, where you can have a Captain who isn't a captain, or a Commander who isn't a captain or a commander, and you can have a lieutenant who can be a captain but normally isn't, and a commander can be a Lieutenant or a Lieutenant-Commander or even a Commander, but a Captain would rarely have been a commander but was often a Captain in command. It's all perfectly plain and simple, dunno what anyone can get confused about.
For added clarity, just yell harder and everyone should be able to work it out. I mean to say, if you're going upwind third gear with overbend creases all over the fathead and max track back on the headie, it's plain and simple that you don't want to go human pole in the zone of death at the clearance, ain't it?
Also, speed is best given in furlongs per fortnight, distance in leagues, and visibility in grey gooses. A unit of beauty sufficient to cause the launching of one vessel is, of course, a milliHelen.
the names are fine if confusing for the uninitiated and saying pull the red red one or the green one is all well and good till the sun goes down and there all the same colour and especially hard when sailing on classics where there all white but part of the fun of any sport is learning to master it
I do sailing for the uninitiated. I also use real terms where needed.
port and starboard are pretty standard, but I can still use pointy end or arse end depending on who's on the boat with me.
the lines can be confusing so I relabelled them. They're colour coded too.
So I use traffic lights for the three reefs - red yellow green
but their labels are, well, pretty self evident. don't click the picture link if you don't like swearing. I have two banks of clutches with labels thus:www.facebook.com/photo.php?fbid=10151863350139084&set=a.472636294083.262494.556624083&type=3&theater
my favourite is the main sheet: scream if ya wanna go faster.
My Missus is totally dyslexic, so the bow is 'the back' and cockpit is 'the front'.
However now she's telling me to use the terms Port and Starb'd because she's
got those sussed and 'left and right' just confuse her.
