I have found that clients often do not know what they are looking for. That often the right answer is not the answer they are seeking. The real skill is in the questions you ask. They should not make the customer feel like a dunce, but they have to shed light on what the customer really needs or what they really want. What they want is often more easy to provide than what they need, which sometimes you just have to shrug and provide. You may know that X will be better, but if they want Y, then you give them Y. When they realise X was better, you get another job transforming Y into X.
You are a consultant, as well as a provider, so you try to explain X is best, but ultimately you only have one question to answer. "What can I do for you today, right now, that will help you solve the problem you have". You will not solve all their problems, and it is hard to bill for consultancy, so try to minimise it. Get a clear goal, a clear measurable outcome, an agreed price and deliver. Then get paid and start to talk about what next, how else you can help. In that way one time buyers become long term loyal customers.
Is this communication issue because I am doing very low-rated jobs, and due to the price policy the customers allow themselves not to handle their tasks in a proper, comprehensive way?
No, it never changes, whatever the price of the project. In fact the bigger the price tag the worse it can get.
How can I improve this communication?
Whenever you are communicating just keep this at the forefront of your mind. You are trying to get them to agree to a set of tasks that represent a body of work you are going to get paid for. So do not discuss at length why blue is colder than red, or why red signifies danger, as them "would they prefer that in blue or red?" When they say in red you write down "1. Blocks in red". When you have enough tasks written down to represent a fair chunk of the work you are ready to offer a quote. Does it matter if you think green is the best colour, or if a bluey red is best? No, of course not. So do not dwell on it. If they say "what colour do you think this should be" you respond with "what colours are you considering". They say "Blue or Green" and you say "I think green, shall we go with green?"
It is a game of turning their random thoughts into tasks you can do for them. Once you get the hang of it, it is great fun and often the best part of the project. Personally I love the planning stage, especially with a chatty customer that is unsure of what they want. They are like incredibly rare golden geese, with lots of golden eggs to lay for you :-)