I have a friend who does costume design, I asked for her thoughts on Ten's outfits, and this is the responce she gave me. More of her work can be found here: http://www.kgleave.com/
So here's what I've got. Let me know if it's totally not helpful at all. :) As far as garments go, this is a pretty simple one.
Front View: Seams are highlighted in yellow.
The seam along the under-arm and side would go all the way through the colored band at the sleeve hem. But the seam along the top of sleeve and shoulder would stop before the colored band. The Mandarin collar would have a seam where it meets the rest of the tunic. Because the right half of the garment overlaps the left, I would add a small shadow (where the green lines are). Nothing too drastic, just enough to show that it's an overlap, not another seam.
Pretty much the same as the front. Clothing before 800 AD stayed pretty simple. :) The sash he wears over his tunic would have no seams. Traditionally, it would be folded over and tucked in, so it appeared to be one continuous band.
The pants would have seams along both the outside and inside of the leg (think jeans). There would also be some pretty interesting things happening seam-wise in the crotch area, but I don't know how much attention to want to draw to that. :) I would just join the two inner leg seams when they meet, and leave it at that. There wouldn't be a vertical seam (like where the zipper is on jeans). That's not going to be figured out for several hundred years.
I would suggest cheating the side seams on the pants toward the back a bit. If the seams on the tunic and pants line up exactly, it'll look like a jumpsuit. Keeping them separate will emphasize that it's two different garments.
Traditionally, silk was reserved for the upper class of China. Monks and anyone of medium-low social rank would wear hemp, or rough cotton. Because fabric was always woven to each person's specific measurements, there wouldn't be any visible hems or stitching. You can see how the fabric made on a loom just sort of ends nicely, where the cut fabric has to be folded and stitched so it won't fray.
Here's a close up of some hand woven hemp:
Fabric dyes of this era were made mainly of plants. The red would have been dyed with Munjeet root, and the yellow with Tumeric (if you're looking for exact color references).
Those are the basics. Let me know if you're looking for anything else. :)