Assassination n00b.

[Archonsod]

One handy thing I tend to find with assassins is giving them items which will cause problems in your opponent's territories too. A bane venom charm (or the sword with a similar effect) which causes disease and poison, if wielded by a suitably immune assassin, can be neat. You can do the same thing with a scout, however if your assassin can take out commanders too you can prevent portions of his army leaving the province for a couple of turns.