If a leather bridle is too stiff, it will be difficult to handle and uncomfortable to put on a horse. Leather stiffens when it dries out and is not often used. If you have not been using the bridle or you have purchased a used one that has been put away for some time, it is important to soften it before you put it on your mount. Conditioning leather softens it and keeps it in good condition.
Wet a sponge and rub it a few times over a bar of saddle soap.
Rub the soapy sponge against the surface of the leather bridle. Before softening a leather bridle, you need to ensure that all of the dirt is off of it; dirt, as well as dryness, can make the leather stiff.
Allow the leather to sit out until it is dry to the touch.
Apply a small amount of neat's-foot oil to a clean rag.
Rub the neat's-foot oil over the surface of the leather bridle, allowing the oil to soak in. The oil rehydrates the leather and makes it softer.
Inspect the leather bridle. If it is still stiff, apply more neat's-foot oil. It can take more than three coats to get the leather feeling soft and supple.
Use natural neat's-foot oil instead of the kind with a petroleum base. A petroleum-based oil rots the stitching on the bridle.