take care where you hit during impact play
even a flogger can injure during impact play, so take care that you don't use it in areas where the skin is thin or over places where there are organs close to the surface, In particular avoid spots like over the kidneys or where there's not much padding over joints. if you're new or fairly inexperienced, keep impacts on the shoulders or butt, where it's hard to do someone real injury. or use a toy that's near impossible to hurt someone with, like a suede flogger or roohide galley whip, both of these make good warmup toys, too. hard impact toys like dragontails or latigo leather floggers, quirts or suchlike, should be reserved for further play. but some like mop floggers, are good for both the warmup and further play, it all depends on how you use them. if you're not sure about a toy, try using it on the inside of your thigh, that's a good way to judge how hard to swing it, and what it will feel like to your sub.
