This method basically consists of keeping track of your thoughts, following thought tracks, finding common thoughts, breaking down thoughts, questioning thoughts and finding positive counter thoughts.
Firstly you just need to write down thoughts that you have. I'll go through it all with an example so you can see how it's done.
Thought: I'm such a failure
Then you need to work out where this came from; the reasons behind this thought and they will be there. They never come from no-where.
Reason behind thought: I got a low mark in my test.
This is rather vague so you need to be more detailed in what you say.
Reason behind thought: I only got 30/35 when in all my other tests I've got 33, 34 and 35.
Then look to see what else builds up this thought.
Other reasons behind thought: Lots of people got higher than me.
Again this rather vague.
Other reasons behind thought: My two best friends got 33/35 and 34/35.
You then need to follow through your thought track and work out how you got from a low mark to being a failure and all the thoughts that your mind is running through
--I got a low mark in my test
--I've failed
--I never do anything right
--I've let myself down
--I've let my parents down
--I always let people down
--I'm hopeless
--I'm not worth bothering with
--People are better off without me
--I may as well be dead
We broke down the first thought down from I got a low mark in my test to I only got 30/35 when in all my other tests I've got 33, 34 and 35 .
You then need to do the same with the rest of these thoughts. Make sure to be concise rather than vague. This way you can often spot generalisations, black and white thinking (in this case thinking you are either perfect or a failure) and other depressive ways of thinking.
Using our first thought we can see that our concise thoughts are very different. You can then look at this and challenge it's link to being a failure.
Challenge: Does getting a lower than before mean I've failed?
Challenge: Is 30 really such a low mark?
Challenge: Does getting a lower mark than my friends make me a failure?
Challenge: Isn't this just a one-off occurence?
Challenge: Don't I succeed in lots of other things?
etc etc
Once you can start challenging and questioning these thoughts you can start replacing them with positive thoughts. Try to find three positive counter thoughts for each negative thought. You don't necesarily have to believe them totally at first but you can work at building your confidence in the strength of believing your positive thoughts if you repeat this process. You can always keep track of how strongly you believe these thoughts (negative and positive) through percentages and watch the negative thoughts percent fall and the positive thoughts percent rise.
Positive counter thought: I actually got higher than the majority of people
Positive counter thought: My teacher praised me for my results.
Positive counter thought: I did really well in my French test last week.
Positive counter thought: I'm a really great friend and a good listener.
Positive counter thought: I usually get excellent marks; this isn't that important.
etc etc
Do this for your first thought in the series. If you then feel better about the situation you can leave it or you can go on to find positive counter thoughts for each of the thoughts in your series. That is what I would reccomend doing with common negative thoughts-thoughts that occur a lot of the time.
These methods are best done regurlarly and you should write them down and keep hold of them. You can either do them alone, with family members, with friends or if you want I can always do my best to help. Don't give up half way through-always follow through to the end even if you're feeling really bad and feel that your positive thoughts are rubbish, you need to work through them and get them down so you can repeat them to yourself and gradually build them up in your head.
These methods don't work for everyone but they can be extremely useful and will help you in the short and long term to understand yourself better and fight negative thoughts if you stick them out.