Rigging in Maya; 'connection editor', 'expression editor' and 'Set Driven Key'

Using the connection editor in Maya to connect finger controllers (blue flags) to the joints.

Click on the relevant controller, in this case the Left Pinky Contoller and load it into the left column of the connection editor.

Select the joint you wish to move (showing as 'green' selection) in the model, and within a blue highlight line in the connection editor.

Select which rotation axis you wish it to connect to, on the right hand panel (in this case the Rotation X).

 Using the 'Set Driven Key' commands in Maya, to select drivers (in this case the foot control) and the driven (foot locators to make the feet bank)

 Creating simple 'expressions' (simple mathematic MEL script) for the forearm joint. An additional forearm joint was inserted into the arm.
Without this additional joint, if the wrist is rotated 90 degrees, then the geometry and associated textures can become very deformed...particularly textures such as clothing or tatoos.
By creating an expression, the forearm can also rotation, say by 45 degrees, keeping the geometry and textures between the elbow and wrist in tact.
Image below shows the Expression Editor floating panel with the objects (left panel) and rotation axis (right panel) and the 'new' expression (script) highlighted in blue.

 Flag shaped finger controllers, drawn with nurbs curves (snapped to the grid in the front view panel) and then respositioned. The centre pivot of each flag was moved to the bottom of the flag 'pole' and then snapped to the finger knuckle joint.

 Testing the controllers and the rotation of the finger joints

Showing the contollers mirrored.
Blue for left and red for right.