Sometimes it's a long learning process, but keep at it.
A few tips (from firsthand experience)
Never drop cold (well below 32º F) lead into a pot of melted lead! (moisture forms and you get a mild explosion of hot lead - it will stick to human flesh and continue to burn!)
Never spill water or coffee into a lead pot! (same results as above)
Wear long sleeves, gloves, and eye protection at all times. (especially if you do one of the above tricks)
Have good ventilation while casting.