To construct my ATC I first make a sandwich of backing fabric / vleisofix / batting / vleisofix , and iron to make a unit.
I then either sew my ATC top or use a piece of fabric and vleisofix the 'bits' on.
This I then iron altogether.
I usually then cut to my 2/1/2 x 3/1/2 finished size before quilting.
To finish I either do a straight or zig-zag stitch several times around the outside.
If the back has ended up particularily messy I will then vleisofix on another backing, and do a couple more rounds of stitching around the outside.