Your subconscious mind plays a pivotal role in shaping your destiny. It is a storehouse of your memories. It makes no distinction regarding the input and accept everything coming from the conscious mind. Whatever your conscious mind sees, hear, smell, feel and experience are all gets stored in subconscious mind.
Further, in accordance with law of nature, whatever your subconscious mind gets, return the same in form of impulses, desire, passion to your conscious mind. If it is filled with positivity, then it will send the positive impression to your conscious mind and on the other hand, if it is filled with negativity, it will send the negative impression to your conscious mind.
Hence, you should stop feeding your subconscious mind with all sort of negativity such as anger, jealousy, frustration, inferiority complex and like of the same. The moment you stop feeding your subconscious mind with negativity; you develop confidence in yourself to handle any given situation with positive attitude.
The way to stop negativity to enter subconscious mind is to start feeding it with positivity. You have to put a filter of choice on the gate of subconscious mind, which is your conscious mind through which all the memories enter in your subconscious mind. Make a conscious effort to filter away the impurities and focus on all sort of positivity so that it goes into your subconscious mind and gets stored.
To sum up, as your subconscious mind develops attitude and behaviours for you based on stored memories, so you should feed it with all sort of positivity. Practicing concentration and detachment also help you to stop feeding it with negativity. While concentration will guard your conscious mind to focus on positivity, detachment will ward off the emotional vices to get way to enter subconscious mind.