The best way to stay safe (and this goes for everything in life) is to not be stupid. ;-)
But seriously, I only use mechanicals, and I've never had a problem. But if you're paranoid about them, some basic things to do/not do:
- Use IMR
batteries over Li-ion
- Don't stack
any batteries
- Ensure the
mod has proper venting
- Buy a VapeSafe fuse (this will cut off connection if it detects a short)
- Make sure to keep the connections (and the mod itself) clean and polished
The only time you might want to be extra careful is if you're using a rebuildable atomizer (buy a multi-meter to test resistance).
Mechanicals aren't scary, and you can't beat their reliability. They might Like I said above, the important thing to do is simply not be stupid with them.