I find that dutch stay in a little better on me, as passing the hair under rather than over seems to trap the layers better, and I also get a nicer wave from dutch than french, but there's not much in it. Fishtail braids are lovely and a bit different, and still look good when they get a bit messy.
try googling missysue, a blogger who does loads of braided styles. We renewed our vows recently and I wore my hair partially french braided - backcombed the front so it had volume, side part and did a french braid which was loose and quite volumised down my hairline to my ear then finished braiding that section. Curled the rest of my hair, swept it over my shoulder then pinned the braid across my head so it looked like the braid was holding my hair over my shoulder, then added a lovely fresh flower vine. You can do lots with braids!