A sub-editor has to, without end, develop his skills at work. It's a job filled with pitfalls. But one thing that has really helped me as a sub is the Online and Off Line column that appears in The Hindu every Monday.
The appointment of a readers' editor was highly controversial, with many in the media calling it a dummy post. But I find the column and more than that the daily correction of errors that appears in The Hindu's centre page useful.
Your opinion may differ about how good a job the readers' editor is doing, but try and read the column, particularly if you are a journalist.