sorry i know it was a while since you asked about this but I do normally put some herbs in it, just really what kinds you like and also grated breadcrumbs. Sometimes sprinkle some grated cheese through, and even little bits of chopped bacon.
I've just made lamb burgers. Put 1/2 pkt of Sainsbury's lamb mince in processor with 1\2 onion roughly chopped and 2 teaspoons ready made mint sauce. Whizz up til pulverised then do other half pkt of mince. (Your processor may be big enough to hold the whole pkt.) Form into burgers. Cook and serve in buns with plain yogourt mixed with mint sauce to taste. Delicious. Plain and simple.