I've never worked with variegated fibre before and so I'm learning a lot in my rose medallion sachet. I usually do cross stitch using the Danish Method and the loop start neither of these methods work with variegated stranded cotton.
Firstly I had to learn how to do single stitching cross stitch the English Method on linen. As the kit pattern politely instructed me:
When working with multicoloured threads always complete each cross stitch as you go or the colour of the top and bottom stitches may vary, and make the work look "muddy".
They also included a wee picture of how to do the English Method but it was on aida! So I had to find a site showing you how to do it on linen, the article Building a Better Cross Stitch is great.
Another thing with variegated thread is that you have to work out where to lay the sections of colour. I have tried to lay the sections of colour symmetrically when they need to be but they will never be perfect.
You also have to think about where you cut the thread and start the stitches again. When you cut the thread its best to do in the middle of a colour section like the black line in the picture to the right. So when you finish the length you make sure you start the stitches from where you cut from the main lot of thread and rather than put the thread in the needle as this will be the last bit of thread you use.