First, try to discover his passions and interests. Is he a reader? Does he enjoy sports? Gardening? Auto enthusiast?
Once you discover what he loves, the choices get much easier.
A lot of guys wear jewelry these days. If he wears bracelets or charms, that makes shopping easier too.
Of course, one of my hand mad dream catchers would please just about anyone :-) and I custom make them too. They may be a bit expensive for a first gift though.
It's always tough to choose a gift, but just put some thought into it and you will be fine.