What else can you sell at a Barber Shop besides hair products?

I opened a barber shop about 7 months ago. I am currently remodeling the whole thing and would like to get ideas of what else can I sell within the shop besides, your typical hair gels. Most guys around here like to buy Pro Club (plain white t-shirts) in little local stores; therefore I am going to include them myself in here as well as hats (baseball)...any other ideas of what else can I sell?