Yes @steve10 this is good advice. I would add that it helps a lot to only check your portfolio itself when you intend on buying or selling.
Emotion needs to be taken out of the picture. If you are watching a monetary figure go up and down you will be pulled emotionally up and down along with it.
In an effort to implement this, I only ever log into my trading account when I want to buy/sell. I know my positions and can observe share price levels from other sources without keeping eyeballs on monetary figures on a daily basis. I have a self wealth trading account, but have commsec access to view market depth/charts etc. I don't trade with commsec as they are a rip off, but their platform is good for observing market action. Currently I probably only access/view my self wealth account (my actual portfolio) once every 6-8 weeks or so.
I find taking your eyes off the $ makes the big retraces a lot easier to ride out. Actually the difference is night and day: I can't recommend it enough, especially if you have long term intentions but are getting a bit jittery with your thumbs.
Another thing you can do is view your portfolio in greyscale. The pyschology of colour (green and red specifically) is fascinating and intrinsically manipulative to human well being based on how we use those colours in day to day life. Don't be pulled around by your emotions in the market if you can help it.
(20min delay)