What about a simple Barbecue Apron. Something in a simple calico or plain cotton etc.
Hankies with an embroidered letter on it or just DAD.
A simple coin purse. (Sue Dewsbury's zipper purse)
Love Chris
All I can think of is small golf towels if he plays golf and small bags for the T's that you can clip onto the trolley. Shoe bag too
Other is initial hankies.
Cheap plain t-shirt put on small golfer or other small design, will make them look far more expensive. Will be interesting to see other suggestions lol, very difficult for men.