If you'd like to use the L/S/D (heh) system of old England but want still more flavor, you can keep things interesting by using all the different value of coins that were used over the past 600 years or so...
Farthing copper
Ha-Penny silver = 2 farthings
Penny silver = 4 farthings
Penny copper = 4 farthings in a different kingdom
Tuppence silver = 2 pennies
Half-Groat silver = 2 pennies but from a different kingdom
Three Pence silver = 3 pennies
Four Pence silver = 4 pennies
Groat silver = 4 pennies but from that different kingdom
Sixpence silver = 6 pennies
Shilling silver = 12 pennies
Thaler silver = 12 pennies in another kingdom
Florin silver = 2 shillings in another kingdom
Half Crown gold = 2 shillings, 6 pennies
Crown gold = 5 shillings
Half Eagle gold = 10 shillings in another kingdom
Eagle gold = 1 pound in another kingdom
Half Sovereign gold = 10 shillings
Sovereign gold = 1 pound
Half Guinea gold = 10 shillings, 6 pennies in another kingdom
Guinea gold = 1 pound, 1 shilling in another kingdom
These would all be in (relatively
) common circulation in your land and would be the coins of the local realm & the ones near it. This would give a flavor of the coinage of the late medieval to early renaissance era. It's also very easy to drop in names like mark, franc, libra, and so forth from history as well. These all sound odd but since most are built off the same basic relationships of copper/silver/gold inherited from the Romans.
I originally came up with this list for a HARP game set in an alternate Wales. Hope this is of some use or interest to someone here.
