Cheap tins of dog / cat food scattered around your safe-backstop-bait area works well (or stuff like dog biscuits etc as it keeps them in the area a while). Scatter late evening if you can. Old saying was feed for 6 days and shoot him on the 7th.
Trailcam is brilliant for this though - keeps track of what time of day the fox(es) are visiting as they can be really routine. After 5 or 6 days they will settle into a routine and you just need a bit of patience and you'll be successful.
The other thing you can do to avoid flashing the lamp around is feed them out of something metallic (dog food tins in old baking trays etc) so they rattle when they are feeding. Allows you to get ready, flick on the lamp and shoot within seconds.