Supervise children while they're using the trampoline.
A safety enclosure can help prevent falls but it's no substitute for good safety padding and a sturdy frame, or for sensible use of the trampoline.
Even with an enclosure in place, kids still need to play safely on the trampoline and under adult supervision.
Don't let kids bounce against the netting on purpose.
One child at a time on the trampoline. Accidents are more likely to occur when more than one child is playing on the trampoline.
Large trampolines are not recommended for kids under six.
Clear safety rules such as "one at a time", "bare feet only", and "do not use when wet" are good boundaries to set early on.
Jump only in the middle of the trampoline and don't jump off the trampoline when finished.
To control bounce, teach your child to focus their eyes on the trampoline.
If you have an older trampoline, consider getting it retrofitted with a frame padding system that's compliant with the current standard. Or replace the old trampoline completely.