Flogging
The most important part of a flogger are the falls also called lashes, thongs, tresses, strands, etc. These falls are made of different materials, in different styles and with different ends or tips. Handle and knob designs are mostly a matter of personal taste as well as the maker's signature (especially in the knobs). But the falls make a very real difference in the sensation delivered by the flogger.
When applied to your subject most Floggers most fall somewhere between being thuddy or stingy. A thuddy flogger delivers a deep, pounding sensation. Used moderately, it can feel something like a massage. Stingy floggers deliver a much sharper sensation. Some people say they feel two sensations, one when the flogger hits, and another a second or two later. Which flogger you will want to use will depend on the effect you're after, as well as personal preferences. Practically every aspect of the falls contributes to how stingy or thuddy a flogger will feel.
Width: The wider the falls, the thuddier the sensation; thinner tails mean more sting.
Number: Fewer falls equals more sting; more tails equals more thud. The typical flogger has about 15 to 25 falls.
Points: Rounded and square-cut tips are the most gentle; pointed tips are stingy and forked points, doubly so.
Length & Weight: The longer the falls, the heavier they are and the faster the tips will be traveling when they hit their target. Heavier generally translates to thuddier, while faster can mean stingy. The exact effect will depend on the other factors controlling sting versus thud. About 16 to 24 inches is an average length for flogger falls.
Materials Besides the weight, width, length, and point cut, the fall's material matters most. There are a wide variety of leather and other materials available, and each provides a different sensation.
Chamois: The same thing you use to dry your car, chamois is buttery soft and very light. It's rare to find a flogger made out of this stuff, and with good reason: chamois will provide almost no sensation at all! You'll get some noise, a very light skin-level sensation, and not much else.
Plonge: A thin, lightweight, buttery soft cow hide, plonge has a shiny finish and a lush suede side. It is extremely gentle, although it can produce significant sting if used with force. Very few whip makers work in plonge.
Deerskin: A light and velvety hide, deerskin is great for caressing the body, and makes an excellent "warm-up" whip. Lots of noise, but very little impact.
Light Cowhide: Slightly stiffer and heavier than deerskin, light cowhide is used by some whip makers as an "in between" material. It generally has a light thuddy feel.
Elk: Heavier than deerskin, Elk is still fairly soft and compressible. It delivers almost pure thud, but gently so: you can put a lot of force behind a blow without risk of hurting someone.
Full Suede: A bit harder and stiffer than Elk. Mostly thuddy, but can sting a bit if the tips are flicked quickly. Many floggers are some sort of suede, and this is a very versatile and useful material for most players.
Top-Grain Cowhide: These leathers are smooth on one side, creating less friction with the air and more sting on impact. Whip makers seem to generally steer clear of these, perhaps because of the "mismatched" look of the tails.