More cheating — I’ve discovered acrylic markers. The Liquidex ones come in two thicknesses; these are the thin ones. Brilliant for lettering and fine details where even using a fine brush would be clumsy. Only trouble is the colours can’t be mixed, so they’re only really useful where pure colours are needed. As in this Louis Vuitton pattern.
UPDATE (August 2017): Blogging the painting clearly hasn’t got it finished! The problem is I gave it an elaborate background which I don’t think works. I’ll simplify the background and finish it off.