How you wear a boot knife depends on the design of your boot rig. Many boot knives come with a sheath with built-in straps, making the whole process simple and intuitive. Some brands of cowboy and combat boots come with a built-in pocket meant specifically for a boot knife. If you're not lucky enough to have either of these rigs available, use these instructions to stow your knife safely and securely in your boot.
Select your knife. A boot knife should be long enough not to get lost in your boot. If it's too short, it may slide toward the ground. This can be uncomfortable, and it makes accessing your knife much harder.
Put on your boots. Slide your knife, with sheath, into one boot. It should ride on the outside of the boot on the strong side of your body. If you're right-handed, the knife should ride on the outside of your right boot.
Adjust the depth of your knife so that a half-inch of sheath sticks above the boot top.
Using a piece of string (a shoelace also works well), attach the exposed sheath to your calf. Place the center of the string on the flat edge of the exposed sheath. Wrap it twice around the sheath, then twice around your calf. Tie it in place.
If you have only one pair of boots, or a knife for each pair, you can use basic leather-working tools to sew a sheath directly into your boots. Some sheaths come with pre-cut holes for just this purpose. If not, sew through the leather or canvas of your boots, but only wrap the sheath in a web of cord on the inside of the boot.
Be certain to check local laws about concealed weapons and carry-legal knives. Many boot knives are illegal. They may be too long or have a dual-sided blade. Also, many boot rigs fit the legal definition of a concealed weapon. Police rarely have a sense of humor when it comes to carrying concealed knives.