A good comment about using knots from the Boy Scout Handbook. The basic knots, clove hitch, double half hitch, bowline, sheetbend, etc all have two characteristics. First, they hold. but even more important, they are easy to untie. The prinicple danger in bondage is that a ligature obstructs arterial blood flow or to a lesser degree that it obstructs venous return. The effect of obstructing arterial flow is obvious within a minute or two (whereas the venous obstruction takes a half hour or so to damage). The various forms of slip knots cause difficulties because they can be very difficult to untie once they are tight. If you have cut off aterial flow with a line tied with a slip knot you may have to cut the line with a knife or scissors quickly to prevent damage.

If you are a novice at this check with one of the old hands at the game (e.g. BDSM Tourguide) before trying something novel. I would not overly rely on the highly sophisticated rigs utilized by the pro for their highly posed photos. These are primarily designed for their photographic appeal. Talk things though extensively with your sub (a process called setting up a contract) and practice, practice, practice before moving on. Remember it does count how far you go but how much fun you have in getting there.

Above all, be safe.