Here's a little training course before we get to next month's exercise (you'll find these also published in Guitarist Magazine).
The contrary of Doisy's recommendations in his guitar method published in 1801, is to intensively use open strings (he undoubtedly was thinking of differences in sound occuring when playing 'played' strings and 'open' strings, that were at the time, very unstable gut strings).
Nowadays, on a fine-tuned instrument, one can have a very smooth performance. We are going to use the Blue Grass banjo player's technique to extend our guitar vocabulary.
If you are not familiar with these terms, you will find that this very simple scale will give you a few ideas. Don't be stuck on it, just take it from here and play around with it.
You can use whatever comes from it and adjust it to your specific needs. Think of it also as a new option to experience and apply in a variety of situations.