This is one cute slouchy hat!
The blackberry stitch or Trinity stitch (can anything ever look not great in this wonderful stitch pattern?) adds some extra firmness and brings out the beauty of the yarn, especially in the Debbie Bliss “Glen”.

Skills: you should like purling 3 stitches together for this particular stitch pattern because there is lots of it! I would recommend a very pointy needle as for example the Skacel Lace needle. Otherwise the pattern is very detailed.