Position the bed in a corner. This will ensure that two sides of the bed have a solid wall against them, leaving less chance of a child falling off.
Secure the ladder to the bed frame at the foot end of the bed. Removable ladders can slip and loosen, contributing to the danger of children falling. Most beds have hardware included for securing the ladder. If you have an older bed system that does not, drill through the ladder and bed frame, and insert long nuts and bolts to hold the ladder in place.
Install an additional removable guard rail to the open side of the bed. These rails have metal frames, soft sides like play pens and a metal flaps that slip under the mattress. These removable rails are often taller than the permanent rails, giving you an extra measure of safety. Open the flap, lift up the edge of the mattress, and slide the flap underneath. The railing will stand up between the mattress and the permanent guard rail on the bed frame.
Teach your children the bunk bed rules. Tell them playing on the bunk bed is not allowed and that the beds are only for sleeping. Children must always enter and exit the bed using the ladder, not the slats at the end of the bed.