Well Gwilym wanted a sort of modified flat-top cut. That I needed to work out myself, but the clippers on the back and sides, then the thinning shears are very forgiving.
Catrin wanted a pixie cut, which meant taking LOTS of length out of her hair. For that I needed help, so I watched a Youtube video by the salon guy and then cut with the straight shears, using scissor over comb to remove unevenness, a few moments of fervent arrow-prayers and then light use of thinning shears to give a more natural feathering to the back and sides.
She looks very pretty. I feel very thankful.
Meanwhile the doctor came and recommended massage, ibuprofen, stretching etc.