I'm 39yrs old, earn 38k. Single, no kids. Have a mortgage.
I was in a lot of credit card debt for years but I'm now aiming to give 10% of my income (after tax) to charity so about £220/month. I also "gift aid" it.
At the mo, half of that goes to my local church (after all, I would pay membership to any club!) and I think they make certain charity donations out of that eg recently to Ukraine as well as their own running costs.
Then I give about £10 a month direct debit to various charities (DebRA, Salvation Army, local animal rescue, Royal British Legion). And give on a sort of ad-hoc basis to friends doing sponsored things or just something which catches me in the heart if I see it on social media (eg Lissie Harper, the widow of policeman Andrew Harper, Bowel Babe)
I'd be interested to hear what others do.