There are many
Most beekeepers will develop their own methods, but in my view too few include the nucleus as part of their management system. This I think is a pity, as with a little planning there are many things you can do with them, but of course you need to know how the bees are going to react, and this will come with experience and a little knowledge. More mistakes are likely to be made with a nucleus than a full colony, but the benefits can be great.
In my view most beekeepers are far too rigid with colony numbers. I think an apiary should be a fairly fluid thing, with possibly a fairly stable number of honey producing colonies and a varying number of support colonies, mainly nuclei that service them. Colonies can always be reduced by selling or uniting if they get above the desired number.
Here are a few ideas....
I encourage all beekeepers to obtain one or more fairly sound nuc boxes, because you will find many more uses for them than you originally thought. I have listed a few uses above, but an experienced and thoughtful beekeeper will find a lot more.
There are occasions when a nucleus can be used for several purposes, so let me give you a hypothetical situation. If you have a spare queen cell early in the season from a good colony, you can make up a 2 frame nuc from old combs you wish to change. This can be with adhering bees, or the bees shaken off and young bees shaken in from another colony. Leave for 24 hours and give it a queen cell. When the brood emerges and adult bee numbers build up, you can add poor combs from honey producing colonies that need replacing, but without adhering bees.
When the nucleus hive is full you can transfer the unit to a brood chamber, but keep filling with poor combs from your main colonies, minus bees, that you wish to replace. When the brood box is full, you can do a comb change or shook swarm, but during that time you may have had several queens mated in the unit. At any time during the summer you can do what you like with it, such as bolster another colony, or when it is still small you can change places with a colony that is showing signs of swarming, so you are milking flying bees from it.
If you have weaker nuclei you wish to strengthen, then you can change positions. At the end of the season you have an extra colony and have made up any winter losses before they occur. Just think of the advantages, you have the opportunity to raise new queens and test them before they go into full colonies, you are changing combs, helping reduce swarming, making increase, and have a spare queen and bees available if you need them.
Be prepared to move nuclei around the apiary, as they can be weakened of flying bees if they are getting too strong, or strengthened if they need building up. If they need weakening they can be moved in stages towards another colony that is in need of strengthening, then moved some distance away, allowing the flying bees to bolster either a weaker or honey producing colony. I do not subscribe to the view that moving bees and combs increases disease, as my view is that the beekeeper should make disease checking part of their normal inspections, and to be vigilant at all times.
A nucleus can easily be made by either splitting a single colony, or by taking bees and/or frames from several colonies, and giving it either a queen in a cage or queen cell. The buttons on the left will take you to pages of relevant information.
As with all aspects of beekeeping a sound knowledge of the "basics" will help you understand more of what happens inside a hive. In my view nuclei are an important part of apiary management and should be used imaginatively.