@Stuartw Stuart, thought I’d share this with you, maybe as an example of what some folk have been suggesting. And explain it in my words whyich may help: One Chord Vamps - #19 by DavidP And maybe you want to try record something top share in that challenge, get some feedback.
I was improvising over a single chord viz Am, and the strumming patters were the same start to finish.
The notes that make up an Am chord are A C E. I know it has been suggested to just use your ears but I think knowing and making use of just a little bit of chord theory can be helpful.
My improv was mostly in minor pentatonic position 1, which is what Justin teaches first. Before improvising I’d suggest being comfortable with that first minor pentatonic pattern. Work on playing it ascending and descending.
Then people have spoken about ‘targetting chord tones’. What that simply means is that you should start and finish on one of the notes that make up the chord ie an A C or E when you play a few notes. So useful to know where those notes are on the neck in the A minor pentatonic position 1. Just try playing a few notes from the scale and then pause, trying to start and finish on the A C or E. For example you could start playing quarter notes on the beat. Just try A C D C A on the D and G strings. Let the second A ring out for a full count of 4 and repeat. It is not the most creative but should sound musical.
Hope that makes some sense, not adding confusion. Just my way of thinking about it.