My preference is wood, but I now use aluminum the most. You can be creative, also, but choose wood with caution. Overly soft woods will disinegrate from the bottom up. Hardwood is the best. There are several choices one can make, when using ski-pole type hiking poles.
Plastic is lifeless, cold, hard, and slippery.
Foam isn't durable enough. Hard rubber and cork seem to mold to the hand well and are very durable. Make sure the finger grips fit your hands well. The right pole has a red or black dot on top of the hand grip and the left pole has a white or silver dot. The significance is that each pole has a hand strap that has been contoured to best fit each hand.