Let's start with you: just three steps its all it takes
step 1: Be aware - count how many times you silently chastise yourself (or out loud for that matter)
(eg. "Gee, that was silly, " "Stupid me, I xx", "I am no good at that")
step 2: Now you have this count its time to turn each of those negative thoughts around into a more positive statement. First, lets delete the negative thought. So say to yourself "delete". And every time you say something negative quietly repeat "delete".
step 3: For each negative thought write down its opposite and say it to yourselves x 5 plus. You may not believe it just then yet I encourage you to keep doing it.
Create a new habit of cancelling the negative with its positive opposite.
Then, sit back and watch your week change!