Watch the Hopping Around online guitar lesson by Jeff McErlain from 50 Eclectic Blues Licks You MUST Know
Open strings are a great springboard to get around the guitar. Country players know this well.
So here is a cool general principal to follow: If your open strings are in the key you are in, you can use them. Pretty simple but often overlooked in positional playing, I know I didn't think about that for years. Try it, choose a key like A mixolydian, where all your open strings are available. Bounce around using pull-offs and hammer-ons. Just like this lick!