One of the hardest lessons for me to learn was to trade small when I had low conviction. There was a recurring pattern in my trading earlier in my career. I would do well on high conviction trades. The money would burn a hole in my pocket and I would blow it on low conviction trades.
I have since become a lot more disciplined but it still a struggle. I am having a very good year and the temptation to let it roll is strong. I have taken down my exposure to match my low conviction, but the temptation is there every day to take risk. The blog helps me a lot in forcing me to explain my rationale as does my experience of having been through the grinder.