I have long been searching for the 'perfect slipper pattern'. And Woo Hoo!! I think I've found it! The 19 Row Felted Duffers pattern is almost the perfect slipper pattern.
Instead of the 19 rows, I took the suggestion offered in the pattern and knit an additional two rows. 21 rows in total. This makes the slipper come up further along the foot, both on the sides and also on the toe portion. My modified Duffers, shown below, look much more like a traditional slipper
than the slippers knit to pattern.
The origial slippers have a ballet slipper look. Both appealing in their own way, just different.
There is one issue to be aware of though. Once those two extra rows have been knit, the opening for the foot - even before felting - appeared quite small. Not wanting a pair of slippers I couldn't get my foot into, I undid the cast off and re-knit - or that would be re-purled - the last row, increasing the stitch count by a M1 every 7 stitches. This resulted in a more spacious cast off and foot opening.
There is yet one more modification I have in mind, so there is still another pair of Duffers on my winter, knitting horizon. More quick, fun, easy knitting! Woo Hoo!