Well this is my first post here so I thought I'd contribute something before I start learning from others in the tutes and trying out the free scripts.
For this idea you do need a fair bit of cash already. I started this with 20+ mil.
Basically all you need to do it merchant gold ores. Why Gold ores?
-They're price is relatively stable
-High amounts are mined by macro's (as well as some legitimate players)
-High amounts are demanded by smithers.
When buying these ores, you don't automatically go okay, buy lowest price, sell highest. That's what all the noobs are doing and its a waste of time.
Here's what I do.
Click the lowest price, then go 5 coins up, the section between that price and the middle (market) price will be your profit per ore.
If you're ore isn't buying, buy one ore at max price to find out the cheapest price in the GE. I'll show this in an example.
E.g. 1) You buy 1 gold ore at max price.
2) You recieve 1 gold ore plus say 19 coins back.
3) Therefore the cheapest gold ore selling in the GE is equal to the Highest price minus 19 coins.
You should try to make 10-20 coins profit per gold ore (over 20-50k ores).
Eventually you'll come to a point where you're buying suddenly stops, this is not due to you're price. This is a limit that Jagex has imposed on the GE to stop people creating monopolies.
As usual, the rubber chicken running Jagex overacted and the limit is too restrictive. E.g. You can only buy 100 yew longs every few hours.
You can still make some easy free money however, I usually make 500k-2 mil per day. I set up my buys, log out and when I come back later that day most of the time my transactions have gone through.
Good Luck

