Being asked to do changes in the work done is a common freelance problem.
Some freelancers don’t include any revision in the price, so if the client doesn’t like the work done, the client needs to pay more to get the changes he wants.
I believe in offering a high quality work and, if you ask me, within the high quality work is adapting the work to your client tastes. So, in principle I wouldn’t ask more money for reasonable changes.
But there is a limit. Your client has the responsibility to give you clear instructions. Then, after seeing your work it is normal that he suggests minor changes. In the end, he is who better knows his customers.
What is not acceptable is not giving any instruction in the beginning and then ask for changes. You need to decide what is improving your work, then you should it, and what is making you lose time, and you never should lose time.
Most of clients are reasonable people, and it is better to accept son minor changes in order to get them 100% happy. With time you will know them better, and you will need fewer and fewer changes each time.