During our Adobe training courses, we have come to realise that one of our tasks is to rid people of the belief that Illustrator is a difficult program to learn. We find that new users to Adobe Illustrator will often moan that they find the program complex. To solve this problem, there are three main things that we like to point out to everyone who attends our Illustrator classes.
Firstly, we point out to people that they must be on the right tool in order to carry out a given operation. Secondly, we teach them to observe and interpret the rich visual feedback provided by the program as you carry out various operations. Thirdly, we always remind new users of the ease with which you can revert your drawing back to a state prior to the point where something has gone wrong.
If you a new user to a sophisticated program like Illustrator, you cannot be expected to avoid making errors: things may go a little awry or even get completely screwed up. The key thing here is to learn the power of the Undo command. For example, if you accidentally resize an object don't try to manually change it back to the original size, simply go to the Edit menu and choose Undo or use the keyboard shortcut (Control-Z or Command-Z on Apple Mac). If you Undo too many times, you can always use Edit - Redo to move forward again. (The shortcut for the Redo command is Control-Shift-Z.)
The key factor in avoiding these types of errors is to keep looking at the various signals that the program provides, in particular those signals relating to the cursor appearance. For example, if you are attempting to resize a rectangle, you can only do this when your cursor changes to a slanted line with an arrow at each end (This indicates that your cursor is now in the correct position).
Another thing that new users find is that they are unable to carry out a certain operation because it is not permissible under the current circumstances or at that point in time. For example, you want to resize an object and you end up rotating or moving it instead.
Avoiding this problem is not hard. You just have to make sure that you have the right tool selected. So, if you want to manipulate an existing object, you just ensure that you have the Selection tool highlighted. One of the first shortcuts that we teach people who come on our Illustrator training courses is that you can temporarily activate the Selection tool by just pressing the Control key (or Command for Mac users).
If you have just started using a program like Illustrator, it is to be expected that you will make mistakes: things may go a little wrong or even get completely screwed up. The main thing is develop the "Undo reflex". For example, if you move an object by accident, don't try to manually put it back where it was, just choose Undo from the Edit menu or use the keyboard shortcut Control-Z (Command-Z on a Macintosh). If you Undo too much, you can use the Redo command to take you forward again. (The keyboard shortcut for the Redo command is Control-Shift-Z.)
If your effort to create a drawing has gone horribly wrong, the best thing to do is to bite the bullet and choose Revert from the File menu. This is a way of saying "OK, this isn't working. I give up!" The Revert command discards all of the changes you have made to the document since it was last saved and can be another useful way of avoiding unnecessary frustration. | 
