Thinning out - how?

What seeds have you planted?

Quite a lot, but the ones that have prompted the question are chilli seeds

How big are they? What have you sown them in? How closely spaced are they?

I repotted mine a few days ago, but I'd only sown one or two per pot. They were 2-3 inches high, but a bit leggy. Where there were two, I turned out the pot, divided them up as carefully as I could and repotted. If they are very small, hold them by the seed leaves so you don't crush the stem. I replanted mine up to the seed leaves, following advice gained here.

Someone better than me should be along in a bit to tell you how to do it properly.

If they're too thickly sown to pinch the tops off without damaging the others, then just snip the stems with scissors of the ones that need thining. That way you won't risk damaged the roots/other seedlings. Chillies/peppers mind generally are ok - may sulk a bit, but after that they'll pick up.

Depending on what chillies you have sown, you may be a tad late for ripe fruit..

As mrbadexample says, use the seed leaves if the seedlings are still small, even the gentlest touch can crush a seedlings stem, if you're going to tease them apart to pot the thinning out.

I tend to sow chillies around 4 per 3" pot, in a propagator.. that way repotting them on is easy when they're large enough (roots showing at the bottom of the pot), and you don't have the issue of half a tray of modules germinating, whilst the others then are removed as part of the same tray and the temperature drop stops them germinating! Also, you don't need to thin them out then - as when they're large enough to be potted on, you've 4 new plants ready to go in the next pot size up! Anything else, I just snip off as I've said above.. mostly edible ones tough (lettuce, etc) - then just eat 'em! Owt else I compost.

Thin out as Chris says, otherwise transplant (prick out) them like Mr BE says

Me, I sow thinly in the first place, cos I hate thinning & pricking out, far too fiddly

I know my timing is poor, my initial ones all bit the dust being left in the sun by mistake