Well, if you aren't sure if you're thinking is twisted or not, you can still look at
The Ten Ways To Untwist Your Thinking and
The Ten Forms of Twisted Thinking. Those can help not just in dealing with twisted thinking, but in figuring out if one's thinking is twisted.
As for knowing that twisted thinking is something to consider, I find that when I'm feeling like I'm in turmoil is a good time to consider the possibility of twisted thinking... a time when twisted thinking is a distinct possibility.