Ideas for a leaving home present

Just make a contribution to his expenses.
Young people these days have very particular ideas, and even the best thought out gifts may be left behind when they go.
Having said that, I did put together a few travel items as suggested above, and sent them with DS2 as presents for DS3 and girlfriend when they all met up in California for Christmas..

Got a lovely thank you WhatsApp from both of them. The compact cutlery set was especially appreciated.

Your nephew is not backpacking, though, so will have other needs. If money is too abstract an idea, how about gift voucher for a good backpack or suitcase. This is something that benefits from being better quality which he may not be able to afford otherwise.

A Bluetooth speaker for his phone. He can listen to music or the radio on his phone at a good volume.
They are quite small.

I made a small first aid kit when each of my children went abroad, in a plastic see-through bag, so they could see at a glance what was in it. Made all the items as small as possible. As far as I remember, it it included: a box of matches, plasters, needle and thread, disinfectant, ibuprofen, antihistamines. Also gave them a small swiss knife with all the essentials.

I would buy one of the small gifts suggested and when he settles somewhere buy him something for his apartment /house.

A great idea.
A friend's son fell asleep in the afternoon sun in a park and woke to find all his belongings had disappeared - money, cards and all.

That's a good idea!

Anti-theft money belt

Young people can be very careless with money and cards. DS2 rang up from Barcelona to ask me to cancel his cards - they had been in his back pocket. Would you believe it?

I like the idea of a St Christopher as well. Suitable for men and women

I bought my daughter a St Christopher when she went travelling three years ago, and she's never taken it off. Very small and on a longer chain to go under the neck of her t shirt, as I worry about jewellery thieves ripping necklaces off your neck.

A sturdy backpack (of his own choice)

Otherwise a first aid kit
Guide book - or Lonely Planet's Ultimate Travelist: The 500 Best Places on the Planet...Ranked

It depends where he's going - is he travelling or going to stay in one place when he gets there?

ecci53 I posted before your second post obviously my first suggestion is not practical.

Portable first aid kit
Corkscrew
travel towel (they fold up really small and dry quickly)
A travel journal.

Speaking from experience:
tin opener
corkscrew and bottle opener
multi-tool

None of the above to be carried in airline hand baggage.

A travel document holder maybe ?

I only gave money , nowadays I get the bank details and transfer a sum to them , they get a handmade card telling them I have done this

Never gave leaving presents

I gave each of my daughters a set of luggage. - the kind that fits one piece inside the other so didn't take up much room. Various pieces went with them on their travels and they then, when they got their first flats, provided 'top of the wardrobe' storage.

A good basic cookbook.

When mine have left I have always bought a laundry basket and filled it with cleaning products, tea towels, Persil, Comfort and stain remover, dusters, kitchen roll, loo roll and toilet brush and cleaner.

They all found it useful.

Continued......
Nephew is nearly 20, will be going on a 4 week training course, then abroad to look for a job. What can I give him that will be useful, small, portable and possibly something he's going to need that he won't have thought of himself. Any ideas, ladies?