Sugar water. The ph isn't perfect but it beats having them starve over the winter from not having enough honey. Some of the big producers will feed sugar water or high fructose corn syrup and sell the result as honey, from what I hear.
As far as the mechanics, this time of year 2:1 or so sugar to water. Sometimes you can open feed in barrels or buckets with a float of some sort for the bees to land on. You can also put various containers in the hive. Sometimes I open feed, but this time will put a sealed, inverted jar or bucket in the hive on top of the frames of honeycomb. A few tiny holes to allow droplets retained by surface tension to form and the bees will happily store it away for the winter.
As far as the mechanics, this time of year 2:1 or so sugar to water. Sometimes you can open feed in barrels or buckets with a float of some sort for the bees to land on. You can also put various containers in the hive. Sometimes I open feed, but this time will put a sealed, inverted jar or bucket in the hive on top of the frames of honeycomb. A few tiny holes to allow droplets retained by surface tension to form and the bees will happily store it away for the winter.