I too am an old English knitter, taught by my Baba.
When switching from knit to purl and purl to knit, in the same row I always think 'up and over'. Bring your yarn to the front between the needles before you purl and go up and over between the needles to the back before you knit.
Amy's video on the 'seed' stitch, English method is excellent at showing this as the seed stitch is a continuous K1,p1 over and over. So you really get to see the switch happening there.