1. It can be stress about the class itself - things you didn't understand and didn't have time (or the confidence) to ask about as the class progresses.
Tip - Make a quick note of the word (it can be a quick scribble) you didn't understand and look it up or ask the teacher later.
2. Constantly looking at the dictionary (many teachers ask their students not to do this, as it slows down your learning).
Tip - Again try to jot the word down quickly and look it up later, by looking in the dictionary you will actually miss more of the class while you try and find 'that word'.
3. Worries about their personal life, finances, family, relationships. To be a good student (and teacher) you have to try and leave these at the door of the classroom (or window of the skype video!)
Tip - Arrive at the class early or sit for 10 minutes before a skype class and practise speaking english to yourself, just for fun, don't worry if it's not correct, as it will help you to 'get in the mood' for your class.
Teachers use 'fun' exercises at the beginning of their classes to 'loosen up' students, rather than going directly to the more serious learning. It can involve swapping seats and forming groups or by asking the students to say a few sentences about their favourite hobby or pastime.
General Tip _ Imagine you wear different hats for different parts of your life, eg. 'mother hat', 'daughter hat', 'wife hat','work hat' and when you come to class imagine them all piled up to one side, and you are now wearing your 'student hat'. It helps to separate your everyday life from that of a student life - don't forget to put your 'student hat' on when doing your homework! Always make some time and space to study outside of the classes.