The basic premise is correct.
When the market is ranged bound, you buy or short when price is extended from the mean, presumably with some confluence at the aformentioned extension.
When the market is trending, entering on pullbacks, the same.
I'm seriously dumbing it down here but you get the idea.
Ok, let's fast forward to reality.
Now, here's what few speak of, on which timeframe?
The trend, if one is present, is your friend, ok, on which timeframe?
There are times the fast timeframes dictate larger ones, these are often called breakouts. The vast majority of times, the larger timeframes dictate the smaller ones. Faster timeframes are naturally, constantly changing states, bigger timeframes obviously take a bit longer to change them.
Trends and ranges within trends and ranges, takes years and years to master that, and you want to dumb it down to the above and open a futures account?
My advice is do your homework first, learn about what I just typed, then when it clicks, go for it, first on sim, then small cash, and so forth.
Best of luck.
