To shoot silhouette photos you need to be facing the light. What I recommend to you is to shoot early morning or late afternoon, when the sun is rising, or the sun is settling.
If you do people photography, and silhouettes, it is waiting for the right moment. If you take silhouette of someone who is just standing, it will look a little bit boring. Try to find the moment, try to find the time when people are having an interesting body posture, interesting body gesture, and try to create dynamism by using people bodies to create lines and silhouettes. Give us that feeling of action and dynamism!
Instead of trying to silhouette one element, or person, try to layer things. Find places where there is a lot of activity, where you can find lot of people, and try to layer all these people into a clean shot.
The key here is to separate all the silhouettes, because silhouettes are black, so if you put one person behind another one, it is going to be a big black thing. You really need to separate all your layers, all of your elements, to come up with a very clean composition. For this, I suggest to find a place where lot of people are working, if you can access markets, or fisherman on the beach, it will be a lot easier.