Creating some safety nets that allow for experimentation and testing of different strategies and methods will be very helpful. One of the more important safety nets to set up early on is to set buy and sell limits. By setting limits, a person will be able to sell before they lose their gains as a result of an ineffective strategy.
The type of ETF trading that a person is going to do will impact the type of strategy that will work best. If an individual is adding ETF to their established portfolio, the trading strategy will be different than for the person who is going to be trading regularly. Most people who have ETFs in their long term portfolio do not get highly involved in ETF trading strategies.