It only took me two evenings in the end, I went to visit my Nana on Monday and just sat and crocheted while I talked to her. Really pleased with the finished result, I think it looks pretty and I'm loving the colour: it's a cheap acrylic yarn off Ebay: Cygnet chunky. I used a 6mm hook, and this pattern from the wonderful Fiber Flux blog.
I don't think the lines are supposed to be there technically - I think I only crocheted through the top loop or something by mistake - but I quite like the effect :) The pattern's so easy and looks so nice I'm going to buy some nice variegated yarn and make one for a friend's birthday.
It's very snug without being too bulky for Spring: perfect!
I hope all your projects are going well :)