Three tips of aikido

The other day, a colleague from the USA who good at martial arts taught me the important point of aikido. Although he said in Japanese, the contents are as follows, to put it simply in English.

First, don't stare at the opponent. Staring at a specific point of others too much that prevents you from moving rapidly.

Second, don't wait. When someone is trying to beat me, I should step into it.
Don't stop and mustn't step back. 

Third, don't allow somebody no chance to take advantage of one. But then I have to keep relaxing.
It's so difficult for me right now.