Tubefaces
Since taking Adebanji's workshop last month, I've been taking my sketchbook on my daily commutes. If I take the train into London Bridge, I get about 15 minutes of sketching time. I find that these quick sketches really help me loosen up and avoid endless measuring. People can move at any time so it's always a race against time to finish as much as I can.
I've also re-subscribed to the New Master's Academy website after previously having a subscription I'd cancelled. Apart from their courses, they also provide photographs as practice material. The drawing below was made using the same brush pens and pencil as the quick sketches above: