Whether queen cells are produced by “artificial” or “natural” means, the beekeeper needs to understand how the receiving colony will react when they are introduced. Bees are usually quite predictable, but will occasionally do the unexpected.

I will assume the beekeeper has assessed the colony the Q/C has come from and it is from a good colony with the desired characteristics. In an emergency situation where you are in need of a Q/C and the only one available is from a poor colony, then use it. You can always rectify the situation later.

The following points may help you minimize issues when using queen cells.

A queenright colony, or one that has only recently been made queenless, won’t normally accept a queen cell. They will destroy it by chewing it at the side and removing the contents. Although they will realise they are queenless within an hour or so, I would leave the colony queenless for about 8 hours before inserting the Q/C. I have been successful down to a couple of hours, but for the average beekeeper I think the longer time is more reliable.
A colony with laying workers or a drone laying queen won’t accept a queen cell. The situation will need to be remedied first.
If the colony is queenless and has eggs and young larvae, emergency cells will be built, even if a Q/C is given. These will need to be removed before they are sealed, otherwise the colony may swarm with the emerged queen from your selected Q/C. If these are removed others may be built, so they will need removing too.
The safest way of introducing a queen cell is to make the colony queenless for 8-9 days, then remove all emergency cells and introduce your Q/C. This might appear excessive, but I have found that colonies can sometimes “hold back” a few larvae and still make viable emergency cells.
If a Q/C must be given to a colony that has been queenless for less than 8 hours, then protect it. This will prevent the bees from destroying it.
When cutting out natural Q/Cs from a comb, leave as much attached comb as you can. This reduces the chances of damaging the cell and gives you plenty to fix to the comb/frame where it is going.
Find a hole or gap in the comb and gently press the Q/C into the comb. This is usually quite easy with “artificial” Q/Cs, because there is usually some sort of holder that can have the pressure put on, but a natural cell will need to be attached by the comb at the top of the cell.
If there is no convenient hole or gap, then push your thumb into the face of the comb and fix the Q/C there.
Fix Q/Cs on combs with brood on. If there is no brood, then in the area the bees have left for a queen to lay in.
A Q/C that is built on a frame usually has a very thin wax wall where it is fixed to the wood, making it impossible to cut the cell from the frame without damaging it. If a Q/C is attached to the frame or in a difficult place on the comb, such as over a wire, I often find it easier to give the receiving colony the frame with the Q/C on it. If you can’t do this with a Q/C that is on wood, then cut the wood away with the cell attached.
Only leave one Q/C, whatever the size of the colony. If you leave two, there is a chance the colony will swarm with the first virgin queen to emerge, unless the colony is very small. Don’t ever think nuclei or artificially swarmed colonies won’t swarm!
Bees often seem to be unable to detect that a queen cell isn’t viable and will not immediately destroy it.
You can learn a lot from the appearance of a queen cell. Those that are “dimpled” and of medium length are likely to be good. Be careful though, because queen cells that have only just bee sealed are often quite smooth, the bees dimple them as they get older. Compare the length with others, as I find some descriptions unhelpful. The shorter Q/Cs are often poorly nourished. The longer ones usually produce poor queens, as the contents may have become detached from the food.
Emergency Q/Cs and those raised on some plastic cell cups can appear small, but may not be, as there is sometimes a greater depth that is hidden.
When you find Q/Cs in a good colony, don’t destroy them all. I find you can often make use of them later, so I cut out a few good ones as if I am going to use them. Don’t leave them in the sun, but under a hive roof. Sealed Q/Cs will survive for some time out of a hive, certainly for an hour or so. If you can use them you could end up with good spare queens, if you can’t, then no harm is done. If I find I have extra queen cells I will add them to a 2 frame nuc. I have a blog post where i go over 2 frame nucs and how to use them.
Sealed Q/Cs can be “banked”, either in a queenless colony or in the top super of a queenright hive, although I prefer the former. You should be aware that if one emerges they could lead a swarm, or kill the others.
Spare Q/Cs can be put in a mini – nuc for mating, although these will need to be set up. An alternative that will suit the ordinary beekeeper is to make up a two frame nuc and either wait 8 hours before introducing a Q/C, or to protect it. This is quick and easy.