Avoid training your horse to be more fearful
"Conditioned fear is often more difficult to get rid of than true fear" says Italian horseman, BHS Fellow and equine behaviour lecturer Angelo Telatin. "With true fear, the horse can investigate the scary object and learn that it is not scary at all. But with conditioned fear, the horse is afraid of something which is no longer there to investigate. It's hard to explain to him that the scary people are not going to come out when he approaches the water jump"
Avoid training your horse to be afraid of harmless objects. Understand the concept of conditioned fear.