Just thought I'd add one more thing: I try and time my handling sessions around the snake's feeding schedule.
I don't handle when they are hungry, or immediately after they have been fed, and I try to stay away from days when they might be about to defecate, as moving around more during handling will, sure as sh**, lead to sh**.... (learned that the hard and messy way), so it might be a good idea to record feeding and defecation times for a while before you begin a lot of handling.
For example my current adults are fed once every 2 weeks, and usually defecate about 3 - 4 days after feeding, so my prime handling time is between 5 and 10 days after I fed them last.
I'm sure that's overthinking it, but I got sh** on a lot, and nipped occasionally while I was working this out, so it may help.