My method of planting them is this: put a six-inch layer of composted stable manure in the bottom of the container; add a handful of pelleted chicken manure and a smaller handful of general-purpose fertiliser (I use "Growmore"); add a layer of general-purpose compost and place the potato tuber firmly in it, with the rose end (hopefully with chits!) uppermost. Cover the tuber with another layer of compost. By this time the container will be about half full. Place the container in a sheltered place outdoors, preferably under cover like this...
This is one of the two new "Seedling Greenhouses" that I recently bought. They each accommodate at least 8 containers - 10 at a pinch. They will allow the potatoes to get maximum light whilst protecting them from the weather. Emerging potato shoots are particularly vulnerable to frost damage, which is exactly why I have acquired these greenhouses.
You will have noticed that I am using old chicken manure containers for these potatoes, not the new big black containers I bought the other day, which I am reserving for my Second Early / Maincrop potatoes which need more space.
The new greenhouses have a slightly different configuration to the one I had before, having a zip-up opening which is smaller than the top surface. I wonder if it will be any better at coping with rainfall? It will certainly be less convenient when the plants get too tall for the cover to remain closed.
Did you notice that I have weighted-down the greenhouse with a brick at each corner? This is very necessary because it is very light and could easily be blown away by a strong wind.