I posted a prior article about open feeding bees in general, but wanted to add to it with the discussion of open feeding comb honey. This may be a bit different as most beekeepers don't give honey back to their bees. After all, isn't the point to get the honey from the bees!? Well, not always. If you can afford the excess honey to give some back to the bees, it does make for an ideal food supplement compared to sugar water, since it is after all what the bees really would have. In general though, honey fed back to bees should be pasteurized just to help ensure that no potential disease is transferred back to the bees. This risk is all but obsolete, but still a risk.
Sort the Combs: In my case, as someone that performs a lot of bee removals, I encounter a lot of honey in the combs. I've found that trying to sort, keep clean, and contain it for resale during a job is nearly impossible. Instead, during a removal, I simply keep comb honey separate from anything with brood in it. Once home, I freeze it all for a few days to kill off possible pests, and then can store it at room temp (in a sealed container), or immediately feed it out to the bees. If it has brood or open nectar, it will not keep at room temp so it should be kept frozen or fed immediately.
Make sure the bees take it: Once fed out, the bees will quickly clean up the combs, impressively quick. That is, assuming there is not a natural nectar flow. If there is a good nectar flow going, the bees will actually ignore honey set out. They prefer to collect fresh nectar. If this is the case, don't set it out. It will just get filled with pests instead and go to waste. Just keep it frozen or in storage until a dearth comes.
Use a good feeder container: I normally just set the honey out in the buckets it was in from the job. This does limit surface area for the bees to access the combs, but is the easiest thing I can do. More ideal would be to pour it out in a shallow container. Keep in mind there will be liquid honey in the bottom of the bucket that the bees can drown in, so sticks or other aids for the bees to climb on are good. The more you spread the combs out, the faster and more efficiently the bees can clean it up.
Keep it covered: This is a big one. If you're expecting rain, make sure the feeding area is covered. Bees open feeding on honey will tend to get covered with sticky honey to where they can not fly back home easily. If a rain pops up, they can get stranded in the feeding container and drown. Not to mention, you don't want excess water getting in the honey. If you have a covered porch to set it out in that's fine. Otherwise just rig up some sort of canopy or roof over your buckets. Just make sure the cover is secure so it won't blow off, but suspended above the feeding container so the bees can still easily fly in and out.
Keep it cleaned up: As the bees clean up the combs, it's good to get the empty ones out of the way. It helps the bees access the rest. I do this nightly, and go out to the buckets and pick off any combs that have been cleaned up. I put them in a bucket and back in the freezer. Frozen beeswax is actually very brittle, and once frozen can be smashed down to a near powder to save space in the freezer. DO NOT just toss the combs in a bucket and set aside. It will be full of pests. I cannot stress this enough. Once set out, if you are in an area with small hive beetle or wax moth, they will infest it quickly. Few things are as sad as that bucket of wax you wanted to keep turning to a putrid mess of maggots. Once you get a good amount of frozen wax, you can melt it down for further use. It takes a good bit of combs to amount to much appreciable condensed wax.