I now have a pattern available for a similar stripey blanket, using more textured stitches than this version - the ‘big sister’ blanket! It’s called The Allsorts Blanket and can be found here - https://www.ravelry.com/patterns/library/the-allsorts-bla...

Having seen the gorgeous blanket made by Jules of Little Woollie - a mixed stitch make it up as you go along blanket - I wanted to make my own.
Although Jules’s blog gives details of the stitches she used as she went along (as opposed to a completed pattern), I wasn’t able to keep going back to look, so made my own up as I went along!

I used mostly trebles, granny stitch, treble clusters to form scallops and half trebles. I felt double crochet might be too tight a stitch and effect the overall tension of the blanket.

I used acrylic yarn so that the blanket can be safely washed with a variety of different budget brands.
I had nine colours in total -
cream x 2
pale pink x 2
mid pink
aqua
pale blue
mid blue
lemon
pale green
salmon

After stitching in all the ends, I did a row of half trebles all the way round in pale pink, followed by treble clusters in aqua, then pale pink scallop shells in double trebles, with cream double crochet to finish.

UPDATE: Julie has now finished her blanket and the pattern link above takes you to a page on her blog dedicated to it. I have also seen it in the May 2014 edition of Simply Crochet.

Update July 2015. Whilst cruising around Pinterest yesterday, I came across a really nice stripey blanket and followed the link to Ravelry. It was made by a lady called Hannah Davis and at the end she said she had taken inspiration from Julie of Little Woollies blanket - and MINE!! Woo Hoo!! That might explain why mine has been getting so many views lately.
I’ve just been having a little look around her blog not your average crochet and she’s written up her pattern (as has Julie) with loads of photos. It’s absolutely amazing, it really is!! If you’re thinking of making a stripey blanket, I would recommend starting with Hannah’s tutorial. All the stitches explained - including how not to accidentally increase your stitches after a shell row… Thanks Hannah!