For two shades last week, I chose to use methods from both ends of the spectrum: hand-sewing, and Döfix adhesive. (This shade, smaller than 2' x 3', is hanging in my back hallway in front of some draped chain weight I was using to help develop "droop" statistics for my Relaxed Roman shade class!)
I measured and cut all the trim lengths and applied Döfix tape to the wrong side.
With the side hems hand-sewn, the top and bottom basted, and the body of the shades secured with rings, I felt the shade was stable enough to flip it over for the trim application. I opened up the bottom hem so the trim could be applied to the full length. A long straightedge provided a line for laying down the trim.
...and insert the weight bar and finish sewing the sides to the bottom (which I forgot to photograph!)