As for the shaping, you can either do it with your own, wetted, hands, or gadgets are available for the purpose. I have an old, much loved burger press from Lakeland, which I would not like to be without at this time of year (or ever, frankly). They don't seem to sell the one I have anymore, but still stock a similar product.
500g lamb mince
1 small onion, very finely chopped
1 tsp ground cumin
1 tsp ground coriander
2 tsp mint sauce (from a jar)
1 tsp olive oil
Rolls, salad and chips or crisps, to serve
Put all the ingredients in a bowl and squidge them together, with your hands, to mix thoroughly. Divide the mixture equally and shape into burgers (and see above). Cook on the barbecue. or grill under a moderate heat, turning once, until cooked through and just browning nicely on the surface. I love them in a toasted bun with spinach leaves and a blob of natural yoghurt.