Crochet border for ripple blanket

I finished my ripple baby blanket last night and have been agonising over what type of border to add. It's the first crochet border I've done and there are so many options.

I'll run you through what I've done in case you're making the same kind of blanket...

First I did a round in off white - I did two DC for every row (one where the rows tough and one into the side of the stitch) on the sides, and on the ends I filled in the peaks and troughs to give a flat edge. To do this, work 2tr together into each decrease stitch, then 1 tr, 2 HTR, 2DC and finally two slip stitches into the two peak stitches. 

I took this pic of my first attempt which wasn't quite right - I wasn't doing the 2TR together into the same stitch with a treble before and after the 2 x 2TR together. Still, it gives you the approximate idea...

After that I did one round of DC in plum, followed by a fan pattern in mocha.

The pattern for the fan is...

Join with a slip stitch wherever you like, then do a DC into the same stitch. Skip one stitch then work 5TR into the next stitch, skip one stitch then slip stitch into the next stitch. Repeat around - at the corners, fudge it so you're working the fan into the corner stitch, but do 7TR into the corner.

Once I've finished, I'll post a full summary of the project :)