Military regulation dictates blousing your pant cuffs at the top of your boots. There are a number of reasons for doing this. It prevents the cuff of your pant from getting caught on things, and it keep bugs and other critters out of your boots and from climbing up your leg. U.S. military battle dress uniforms come with blousing straps sewn into the cuff, but many service personnel choose to use commercial blousing products.
Lace and tie your boots all the way up. It does no good to blouse your trousers over sloppy or open boots.
Wrap the commercial blousing strap around your calf just above your boot and secure it. You secure some blousing straps by connecting a metal hook to an eyelet. Other blousing strap designs use plastic hooks and loop strips. With military issue BDUs, you can simply tie the ends of the sewn-in straps snug, but not tight, around your calf.
Pull the cuff of your pant a few inches below the blousing strap if you are using a commercial strap.
Grab the strap through the material of the trouser leg above the cuff and pull it away from your leg, creating a space between the strap and your leg.
Roll the bottom of the trouser leg under the strap all the way around your leg. For trousers with sewn-in straps, just roll the pant leg down around the outside of the secured strap.
Pull the rolled edge of the pant down over the top of your boot to complete the procedure.