Having kids and elders in the house can give you some worrying reasons. Older people have little stability while small children do not understand risks. Making things safe around the house will bring you comfort.
First of all you should have night-lights in your stair halls. They use little energy and make walking safe when the house is dark. Keep a supply of the appropriate light bulbs in the house so that you can always replace a burnout promptly.
Falls are great risks for older people. So that they do not fall on the stairs, it is first important that they actually see them. Take some reflective tape and a pair of scissors and mark the treads with the tape. It glows in the dark so it is useful at night or when there are power outages. You will place the strip of tape on the top, front edge of the tread on its entire length and flatten it well. Clean the stairs before trying to tape the treads so that there is maximum adherence power. Also mark any uneven surface that may cause a person with poor mobility and eyesight to trip with reflective tape.
Small children moving around in walkers most definitely can not go down the stairs on their own. Until the child understands that he or she should stay away from the stairs, it is a good idea to install child safety gates. Make sure that the gate is well secured to the walls. Pressure mounted gates will clamp to the sides of the staircase by means of pressure. You can use straps and screws for securing such a system gate to the walls. What is even better is that you select gates with hardware mounts. Be careful to securely screw them into the wall and check them regularly to see that they are still fastened tightly.