I've been making circle skirts lately, and one very important thing about circle skirts is the flow. If the hem is too heavy it will stiffen the bottom of the skirt and it just won't fall well. My favourite solution is bias binding. I've been making my own, and today I got really detailed about it, so I thought I'd take some photos and post the process.
Tip 1: Use bed sheets
First, you need wide fabric, or you'll have to cut lots of short strips. I've been saving old bed sheets (and sometimes buying new flat sheets on sale) for making stuff out of, and they're a great source of much-wider-than-usual fabric.
Tip 2: Check your angle
Then you need to fold your fabric along the diagonal. If you want to avoid puckering you need to get this angle right. The grain should be at 45° angle to the folded edge.
I used the 45° triangle from a maths set. It's worth fiddling with this to get it right, because small mistakes in the angle will result in puckering when it comes to sewing on the binding.
I have a tool (something like this) for making bias tape, and it requires a strip 48mm wide. I usually bodge this number to some extent, but I really felt like being exact tonight. So I got out my rarely-used rotary cutting tool and cutting mat*. My metal ruler is about 55mm wide, so I added little notches at either end to help line it up with the edge:
I can hardly make out the notch myself in this photo, but there's something I like about the composition so I'll leave it in :)
* my favourite sound in all the world is a good scissors cutting through two layers of fabric on a smooth table. Rotary cutting tools are all very well, but they will never replace my scissors in my heart.