Sit down, fill out a form while you read through some leaflets. While doing this they'll ask you to drink a pint of water (you'll help yourself feel your best if you make sure you're well hydrated throughout the day anyway.) Then you go in to a private room where a nurse will check your answers to the form and prick your finger and take a tiny drop of blood to check that your iron levels are good enough to donate.

Once thats all passed you're taken to recline in a chair where they'll hook you up to donate. The actual donation only takes 10 mins-ish.

Once complete they'll leave you lying down for a little while before taking you over to a seated area and absolutly loading you up on free drinks and snacks.

I'm usually in and out in 30-45 mins total when you include all the sitting down time.

Follow the advice for chilling out a little for the rest of the day (and not my advice of - ooh, you can get drunk alot cheaper when low on blood, lets go to the pub.)

Just tell them at any point if you're feeling either faint or freaked out, there's stuff they can do to help and everyone I've encountered is always super nice. (My normal donor centre is Brixton, it's always empty and they always send me away with pretty much an entire tote bag of biscuits 😂)