Plant your spring bulbs from September until a week or so before the frost sinks into the ground. The further north, the earlier planting. Plant in early autumn. The bulbs are then in the best condition and they get plenty of time to establish themselves before winter.
Make a hole in the soil and plant the onion with the pointy part up at two to three times the depth of the onion's height. Feel free to put many bulbs together to create effect and fill the flowerbed. If you place the bulbs at different depths, they bloom differently early. In this way, you can get a longer bloom.
It is perfectly fine to put spring bulbs in pots. Have soil mixed with sand for good drainage and mix in bone meal. Use pots that can withstand frost and moisture and with drainage holes. It is always better with a slightly larger pot. A plastic pot is the safest choice as it can withstand frost. Keep in mind that the soil in a pot will be colder than in the open field. Place it protected from rain or bury it in the soil or compost and cover with leaves. You can leave out planting at the far end of the pot, so the outer layer of soil acts as an insulation against the cold. Alternatively, insulate the outside of the pot. Store the pot outdoors (but protect from water, snow and extreme cold) or in a cold greenhouse or some cool place indoors. The bulb needs a continuous period of cold (below 9 degrees Celsius) to start flowering and should not be kept warmer than that to avoid it starting to germinate. When you see about 5 cm of the stem, you can lift into the house. But please place as cool as possible to prolong the flowering. Another way to prolong flowering is to plant bulbs at different depths.