Go into the market and search for an "Expanded Cargo Hold 1". This item is normally very cheap so you will not lose too much ISK if you mess up.
Step 2
Now I am going to place a buy order for 50 of those cargo holds at 1.500.01 ISK which will cost me 75.600.50 ISK including the broker fees.
Make sure you always make buy orders with .01 more than the highest price on the list since this will make you top of the list when someone sells their item. Make sure you keep this because people will go and try to get the top of the list.
Step 3
Now I have the cargo holds I will sell them for 5.588.31 each which will make me 274.386.02 ISK and a total profit of 198.785.52 ISK.
Step 4
Take this strategy and research what other items you can use this with. Once you start doing this with many items over and over again you will be making billions of ISK each day and all you will be doing is making buy and sell orders!
Once you find these kinds of items add them to your market quick bar but make sure you always keep an eye on the prices to ensure you will make a decent profit. With a profit margin of 375% it's harder to lose on an item like this.