The first one is two dutch braids at the side of the head. When you have finished both sides, use a bobby pin to connect the two braids together. Just open up the pin and slide it in towards that back side of the braids so that it has a little bit of hair from both braids from two or three sections of plaiting. Tie the braids together at the ends with a bow or another hairband.
I like to call this one "Double Dutch," but it is really two half-dutch braids. Part the hair down the middle, put one side in a temporary ponytail, then do a half-dutch braid along the part line. Let out the ponytail and do another half-dutch braid with the remaining hair. Tie the ends together. You can stick a bobby pin in the tails as above, but I didn't think it was necessary. If your braids diverge from each other at the part, you can bobby pin them together so it doesn't destroy the illusion of it looking like a complicated four-strand braid.