Watch the A Page From Jimmy online guitar lesson by Jeff McErlain from 30 Smokin' Blues-Rock Guitar Licks You MUST Know
Here's a fragment of the classic Jimmy Page descending pattern he plays on "Good Times Bad Times". This pattern is extremely useful as (like most patterns) we can use it all over the place. We can use the whole thing or just a fragment of it like I did here.
A good exercise is to carry it on throughout the scale. In this one it uses the first position of the pentatonic scale, then take it through the other 4. It's a great exercise that will find its way into your playing in no time. But for that to happen, you need to PRACTICE the heck out of it! Actively try to use it in different positions and applications while practicing, and then it will come out in your playing. That's actually good advice for just about everything!