I've been casting my entire adult life and have a system that works. Friends who have started were appalled at my precautions but that's literally no skin off my hands, feet or face.
I wear long jeans, closed canvas or leather (not plastic or nylon) shoes or ankle / western boots, wear glasses, long sleeves, use a fan to blow fumes away (may cool the furnace a bit if aimed poorly) and if indoors use a lead rated mask. I've used gloves but have yet to find a pair made of leather or canvas that provide tactile usability so I stay glove-less. Also I make certain that any ingots, molds or ladle/spoon/scrapers I use are dry to prevent steam eruptions.
Lastly if outdoors when (not if in south Florida) it rains, I STOP casting immediately and cover the crucible even though I cast under a 10 foot umbrella again to prevent lead eruptions should water droplets find their way into the lead pot. Oh, it goes without saying, I use only very sturdy table to cast.
Anyone else have things I have not mentioned that you do to prevent accidents?