Unless it is a massive texel lamb I have lambed (and kidded) in "superman" position a few times... lots of lube and a good pull. When I tried to do it textbook I promptly lost the head inside and it ended up a vet job...
however - always have painkiller for afterwards for the ewe/nanny, my vets either give flunixin or loxicom, which cheers the ewes/nannies up in no time...