The first step in being successful in war is to have solid war bases. In nearly all cases, one’s war base will be different than their village-and it should be.
For your village, you want to protect your gold and elixir. For war those don’t matter at all. What matters is protecting your town hall, and at all costs.
Therefore developing a good war base is centered around protecting one’s town hall. If someone wipes out your entire base except for your town hall, they will only get 1 star. So go against your regular thinking in your village design, and don’t worry about elixir and gold storage. They are not important in war. You will not lose any of your gold or elixir in war. If anything, you can use them as a distraction as inexperienced war players typically go after them immediately.
You should design your war base so that in order for someone to attack your town hall, they must go through as many walls and buildings as possible. It should be protected by your BEST defenses.
Here are some examples.
Well protected defenses. TH in center.
Solid base that is very very tough due to concentration of defenses. Traps and bombs are by TH. Highly recommended.