Many are daunted about working without a pattern and shy away from freeform work but there are a few easy guidelines to make your freeform successful and open up this style of beading to you.
Firstly, work with a monotone palette.
Get together a selection of beads in different sizes and shape but all in shades of the same color. Things will be a lot easier if you don't have to think about color changes.
Secondly, know your curves.
Practice working on a strip of peyote, use large beads at one side and small beads at the other, try 8/0 and 11/0 sizes to begin with. As you work you will see that the work willl curve towards the side with the samller beads. Now switch the sides for the beads, using small instead of large and large instead of small....this will make the work straighten up as it curves in the opposite direction.Use one stitch.
On your first attempt stick to one stitch...one you are very comfortable with. Try breaking the work into columns, you can play with curves and even braid the columns, even twist columns before bringing them back together. Once you have created a couple of freeform pieces using one stitch you will be much more confident about adding more stitches.
Go for it.
Don't second guess yourself the first time you try. Freeform work can be embellished, worked over with netting and added to allowing you lots of control to get the finished look you want. There are no rules which means you can't make mistakes :) The more you do freeform work the better you will get at it so don't beat yourself up if your first attempt is not something you would wear....look at the lessons you learned in creating it.
There are tutorials out there that give you some techniques to incorporate into your work. They aren't patterns per se, but give you tips about changing sizes, changing stitches and adding embellishments.