IF LOTS of smaller species are present in the venue, then I’d use either roach or squid sections to target the eels.
If the lake doesn’t contain nuisance fish, then lobworms take some beating, but I’ve also done well on snails, slugs, maggots and lamprey.
Eels are scavengers with a diverse diet, so don’t be afraid to experiment.
There are loads of rig options to try, but to avoid deep-hooking, I use one that incorporates a short hooklink made from 4ins-5ins of 50lb snag leader and small barbless hooks.
My go-to set-up is a ‘snig twig rig’, which has a section of plastic boom threaded on to the hooklink and held in place with two float stops.
This ensures that the eel doesn’t swallow the bait, and I fish it free-running to keep resistance to a minimum.