Outlet Plug, Half Switched - 2 3-Way Switches, Power Supply at Outlet Plug

Wires, Outlet Plugs, and Switch Box

The white wire going between outlet plug and switch 1, and the white wire going between switch 1 & 2, wrap a piece of black electrical tape around both ends to signify that this is a hot wire.

Bare wires not shown in the diagram, all connect together and connected to grounding screw of plug, if a metallic box then grounded to the grounding screw of box. At the switch box, the bare wire gets grounded to box (if a metallic box) and if the switch has a grounding screw then connect to ground also.

If you need to continue an unswitched source of power from the plug then connect the continuing cable to circuit black / white / bare (coming from power supply cable) (black to black, white to white, bare to bare)

Continuing a Switched and Unswitched Source of Power

If you need to continue a switched and unswitched source of power onward then connect by pigtail method the continuing black/red/white/bare cable to...black to black (from power supply cable), red to black (coming from switch 1), white to white (from power supply cable), bare to bare. On the continuing cable, black would be an unswitched hot, red would be a switched hot, white is a neutral, and bare ground. If this continuing cable is going to another half switched plug then black to one brass color screw, red to the other brass color screw, white to silver color screw, bare to box (if metallic) and to grounding screw of plug. Break off joining tab between brass color screws.