Marker pens are only useful if you know where to find them when you need them and they are working when you get them out. More often than not when you eventually do end up with a marker pen of the color that you are looking for it has dried out.
You can keep your marker pens ready to use and fresh by storing them with the caps down. This keeps the ink towards the tip and fresh - ready to use.
One great storage container can be made from an old tin of beans, if your can opener does not leave a sharp edge. Once you have enjoyed your beans soak the empty can in some warm water, the label should just fall away. Wash and dry thoroughly and you have your very own designer pen holder. It may be just an old bean tin but they can look quite trendy when you have 2 or 3 together.