The common thing you would have heard of is using an algorithm or special software to backtest your trading strategies. The reason why is quite straightforward, it is the most common method. Program your strategy, download the data and run the simulation. Then you will instantly see if it would have worked in past market conditions.
Now, for non-programmers, there is the long way: you will have to manually do this by plotting your technical tools on the charts a few times. Now, how will you ensure you are honest with yourself? You could try scrolling back, plotting, then slowly scrolling forward.
You could use rewind features from software such as MotiveWave, ProRealTime, TradeStation, CQG, MultiCharts and TradingView to try to keep you more honest.