It's all about location!
The zander is actually a very easy species to catch. Obviously you need to be using an appropriate method. Livebaits, deadbaits and a whole array of lure techniques will catch them. There is so much to choose from in this respect. Then you might need to be at the water at their feeding time. In coloured water, expect them to feed at any time, and when the water is gin clear, they will most likely turn to night feeding. These are not difficult things to put into practice, and yet many anglers struggle to catch zander.
They are missing the vital link to success - location. Zander have a habit of taking up positions in very localised areas of rivers, drains and stillwaters and finding these places is the key. In my experience on many waters, zander are rarely spread out and are very localised. I can recall many instances where there have been just a couple of zander swims in miles of water. Initially this was determined by simply doing a lot of fishing and moving from swim to swim. When I started boat fishing for them, the screen on the echo-sounder reinforced everything I had worked out.
If you decide to tackle a water that contains zander, I recommend that you bear this in mind. I would keep on the move, trying different swims until you catch one. When you find one, chances are that there will be others nearby as they are pack hunters. Most of the zander swims I have found have been reliable to go back to time after time. Provided that they are not overfished, and other anglers are not onto them, you will have regular good zander fishing which can be enhanced by next working out their feeding times and how these times vary with weather and water conditions. Zander are quite fragile and it is essential to use safe rigs, strike early, and use minimum handling. I prefer to fish for zander in the colder winter months as, just like pike, they do not recover easily where there is low oxygen content in the water or when caught in very deep water.