Revisit old exercises and repertoire
Reviewing previous work can affirm the progress you've made as your old exercises and pieces may now seem easier than a previous run-through. Perhaps you can now up your performance level by adding what you have learned since? Always practice like you are performing: tuning checked, use your footstool or support, have good posture and nails properly buffed.
Restring your guitar
Are your strings sounding a bit dull? Can you vary your dynamics easily? Do your harmonics ring out easily? If not, maybe you need to try out some fresh strings...and while you're at it check out your tuners and frets for wear and tear.That fretboard will probably need cleaning too!
Find new repertoire and exercises
Perhaps you heard some exciting repertoire during our previous concerts or open mics that you want to try. Has your teacher suggested a classic exercise book or a brand new method? Now's the time to check it out.
Research music, listen to music and watch videos
Whether you are working on a specific piece, or have an interest in a specific musical genre, composer or style, there is a myriad of written and recorded work to enlighten you on the internet and hardcopy and e-books on topics ranging from stage fright to tuning systems to biographies. Books and music can be good companions to take to the beach or a picnic. Try a song in a different guitar tuning.

Compose and arrange pieces
If you haven't composed before, start by creating a simple melody and add some chords. If you have experience in writing music on staff lines, take one of your favourite pieces that you haven't heard played on the guitar and arrange it for the guitar on the treble clef (a good fingering exercise!).
Record your music
With a quality recording of your piece, you can be your own adjudicator or share it with someone else for feedback. Play a duet with yourself by recording one part and playing along with it.
Try something new (or old)
Have you seen someone using the latest electronic gadget, software or app and wondered what it was or how it worked? Now is the time to download that new app or software and give it an evaluation. Or try old technology - perhaps you wanted to try playing without nails or try out a Torres tornavoz - go for it!
Connect via video
Consider lessons via video conferencing. Skype, Facetime, Zoom, Jamkazam, and other platforms can get you connected to one or more people for learning and sharing music. A quality external microphone definitely helps improve sound, but even a built-in mic with a pair of headphones can give you a satisfying experience.