SO sometimes referred to as stuffing ties, these loops hold your stuffing in place evenly over your base hessian, on a seat you would normally do a formation as below but when your doing in something like an arm you would change the position to be more like vertical loops, think of gravity and what way your fibre would start to fall and they should hold and stop it falling.
Once you have covered the area you are stuffing with hessian you need to use a springing needle and twine to start creating your bridle ties. Start with a slip knot...
Loop the twine with back stitches leaving about a hands width space, its ok if they are big or small they just need to be even...
Go round in a way that makes sense to you, I like to start in the bottom right hand corner and go round in a clock wise direction. You need to remember so you know how to tighten them later.
Put handfuls of your stuffing into the ties evenly, this is where it helps to use your hands as a guide and make sure that its even and will help the next step which is to get the fibre even and covering the hessian as completely and evenly as poss :)