Cut a 36" length of nymo. Gently stretch it for a few seconds. This relaxes it and keeps it from stretching after it is sewn. Then draw the thread through some conditioner a couple times. I use thread heaven. It really reduces tangling.
Work 3 or 4 backstitches to anchor the thread, come up at your starting point, and pick up 4 seed beads. I have photo step by steps showing how the beads are stitched down. Stitch down the 4 beads along the design line. Stitch back up through the interfacing, coming up between the middle two beads. Run needle through last two beads, snug up the stitch and pick up 4 more beads. When you are through with a line or area, run a double thread through all lines of beads. Begin and end all threads with 3 or 4 back stitches.