Gifts for Father's Day?

Scully

If he's not your father, a Father's Day gift is not required.
If you're looking on behalf of his child (your child together or his children from a prior relationship), make it something age-appropriate.
Birthday gifts: Home cooking is always a great idea - I usually splurge on the best steak I can afford and bbq them (served with his favorite sides and a nice homemade dessert afterward). Our local gas station sells car wash cards that are good for 90 days (1 per day) and Mr Scully loves that.
Listener

Socks :)
I find it hard to buy presents because a lot of presents are not really wanted.
Maybe a case/tool box/chest/organiser for some of his bits and bobs.
mentalclarity

@Scully - like the car wash idea!
Simon

If they like computers (or would like to learn) you can buy a Raspberry Pi kit - lots of interesting projects you can make with them. I'm thinking of making a Karaoke machine.
https://www.raspberrypi.org/