I love traditional horseshoes on walls and hangers made of them (but not in weird combinations - just simple ones), photos of horses and as an artist I like to have lot of art around me - so sculptures and my sketches of horses, nature e.t.c.
There are many ways in which you can add an equestrian touch to your apartment, may it be with subtle details or atmosphere, or with explicit equestrian objects or representations.
On my part, I absolutely love everything related to the Ralph Lauren style interiors, which feature a very polo/Hamptons universe. Only choosing this style already relates to an equestrian universe (colors, objects…). On top of that I like to add black and white horse photographies from artists, or equestrian photography books in the living room. Small statues or stirrups can also add a nice equestrian detail to hold books for example. You can also pick cashmere or wool rugs for your bed or the sofa, which can feature some equestrian illustrations (bridles, horse profile…). You can source many Ralph Lauren inspirations of course by going to their store or website, but also on Pinterest!