My horse seems scared of everything — where do I start?

A horse that appears scared of everything is usually a horse that has never been taught to process fear, not a horse with an unusually high number of specific phobias. The response — heightened alertness, flight tendency, difficulty settling — is a personality and training baseline, not a list of individual fears to address one by one. Start by evaluating the horse's general emotional state in its daily environment before you ever introduce a scary object. Does the horse stand tied quietly? Does it lower its head and relax during grooming? Does it stand calmly when nothing is happening, or is it always scanning and on edge? A horse that cannot stand and relax in a familiar, safe environment needs that baseline relaxation built before any formal desensitization work is productive. Establish a daily routine that is predictable and low-pressure: consistent feeding times, consistent handling, work at the same time each day in a familiar space. Routine itself reduces ambient anxiety in horses that are easily overwhelmed. From that calmer baseline, begin desensitization with the least alarming stimuli available — not tarps and flags on day one, but a plastic bag at fifty feet, a new object placed quietly in the corner of the round pen, unusual footing like a rubber mat. Build the horse's confidence with objects that produce mild curiosity rather than genuine fear before escalating intensity. The goal of early work is not to expose the horse to scary things but to teach it that investigating an unusual thing leads to nothing harmful and earns a release of pressure.