I have found it a challenge to restrict my activity as an investor.  I quess I am a busy person, and feel the need to be doing something, which led to me being impatient and over trading.    

To address this, as a default, I only invest in 1% increments, thereby limiting how much i change my portfolio, and control my "activity bias".   I also conduct deeper research and learning to quench my desire to do something.   There are exeptions to this.   If a thesis breaks, I exit fast, at whatever price I get at the time, and don't look back.  There are also special cases, where I might rapidly buy into a company I know well and have a high conviction in.     

I know 1% doesn't sound like much to you now, but after 20 years of successful investing, it will be.