'Pricking out' is the term gardeners use for moving young seedlings, from the trays or pots from which they were sown, into individual containers so they have the space and nutrients to grow. I love pricking out, it's a sign your seeds have successfully germinated and I find the process of moving seedlings from trays to 9cm pots very mindful.
When your seeds first germinate they produce a set of leaves called 'seed leaves'. These differ from the plants 'true' or main leaves. When the first 2 true leaves appear it's time to prick out the seedlings. If you have a trays of dozens of small seedlings that are germinating rapidly, like poppies or ammi, you might want to prick them out before their first 2 true leaves appear.
Lift the seedling by it's seed leaves, I use a stainless steel tool to help lever the roots from the compost but a plant label, pencil or teaspoon will also do the job. Try and lift as much as the root as possible without damaging it.
Fill a 9cm pot with compost, make a hole in the centre, and carefully ease the root of the seedling into the hole. If the seedlings are starting to get a bit leggy you can plant them fairly deep into the pot, as long as the seed leaves are above the compost. Water, label and place somewhere warm, sunny and protected from frost.
You can watch our How To Prick Out Your Cut Flower Seedlings here