The main technique to apply base details to your patchwork is applique. Some of you who have taken the Spirit Cloth Workshop have seen these technique videos before. I use the same basic techniques for all my work and adapt them to the context of what i am doing.
The ragged methods I am showing here are quick and don't require too much skill. If you are going to put your piece into a heavily used quilt or pillow you may want to consider using turned applique which is the next lesson set. I do find that the ragged method will stand up to washing if your shapes are simple and your pieces are not too small. As with all things, experience will allow you to choose what works best for you. If pieces fall off or degrade over time, it is just an opportunity for mending and learning and those things are just as fulfilling as making.
With the basic ragged method, you just cut, place and invisible baste with small stitches front and back. And then you do any quilting or embellishing right over that. The advantage of the invisible stitches is that you can continue to embellish without the stitching interfering in the look of the piece. It is like thread glue. If you have chosen the collage technique for patchwork, this is one way to begin.
The halo method gives you a nice fray, and a slightly more permanent edge. Draw your shape, do a tiny back stitch all the way around the edge, it is ok if it shows. Then, make tiny cuts all the way around, taking care not to cut the stitches. Scratch the cut edge with your fingernail to rough it up a bit and free some of the loose threads. Washing and drying will enhance the edge further.
For a more permanent and clean edge, the turned methods are the best way to go. I use this method to secure the folded edges against the seam of the patchwork as described in my last lesson. Turning the edges is really quite simple and with a bit of practice, you will find it quite useful for embellishing. Some fabrics are easier than others and in general it is best to stay away form thick or too loosely woven cloth especially those with fancy weaves. I like thin soft fabric the best. These are just some of my basic techniques.
All the turned methods are basically the same, you are turning the raw edge under to hide the fray and create a clean edge. It is easy to start practicing with a straight edge which is a like like hemming. I like to draw my shape and either use the line to guide me by hiding it or by using the line itself to give the shape a sketchy shadow look. I use one strand of embroidery floss for turning. Matching the thread color to the applique itself can hide the stitches better. There are ways to clean up a messy edge with stitch so don't worry.
Simple needle turned edge View Video
Line Guided Applique View Video
Sketch Applique View Video
Applique in the context of the beast...
These applique techniques can be used in combination to enhance the pieced base before going to the stitched embellishment phase. I use the ragged applique often to extend a piece and I use the turned and the ragged methods o in combination to do the initial decoration. Whenever you are using two ragged edges together, be sure to overlap them to make the cloth more secure and avoid gap.