Here is a detailed way you can grow your own chilli plants from seed, there are many different methods.
Fill a 7.5cm pot with seed compost, level and tap to settle. Lightly firm.
Scatter a few seeds across the surface – use what you need, most will germinate. Some of the hotter varieties will take a little longer.
Cover with a thin layer of general compost or seed compost, water and label. Just keep moist, never over water or you will rot the seeds, I use a spray bottle and give them a good spray every few days. Always watch that the compost never dries out.
Put a clear plastic bag over the top and secure with a rubber band. Place in a warm spot or on a windowsill. South facing if possible, it is also possible to pop into the airing cupboard, as it’s the heat that is important at this stage.
Remove bag when seeds have germinated. If using the airing cupboard method, remove once the chillis start to pop there heads up
When seedlings are 2cm tall give each their own 7.5cm pot. They should have at least two sets of leaves by now. And always remember to keep moist.
Pot into a 12cm pot when roots show through drainage holes.
When plants are 20cm tall, stake with a cane, the plants will need to be supported as they get larger.
When plants are 30cm tall, pinch the tops to make new branches. Pinching out will make the plants bushier, this not a must but will insure more pods.
Give high potash feed when first flowers show, also a tomato feed is also a good idea
In May, pot into 5-litre pots, stake and put outside in the greenhouse, if the summer is good they will be fine just outside, chillis are quite hardy, but protect against cold temps with fleece. Keep the feed going as above and enjoy the fruits of your labour.