To start the tips'n'tricks section I figured id start with something simple.
This is a nice quick and easy way to rig a finger to make it quick and easy for an animator to use with just one bone.
First up, make the bones for your finger. I'm gonna stick with simple and go the generic 3 segment finger. But this method can be used for as many as you like!
Open up the DopeSheet and make a driver action.
its good idea to give it a specific name, ie. DRIVER_character
Go to frame 10 and rotate them upwards. Setting a rotation key again.
It doesnt matter how far you rotate them just as long as its the same amount each way.
Create an action constraint on one of the segments and point it at your driver action.
Transform channel : Scale Y
Action Length : -10 to 10
Target Range : 0.5 to 1.5
Convert : Local Space
Couple of tips at this point. In your action, set all the keys to linear so that the scale value and the curl amount is proportionate. I have my scale values at .5 to 1.5 rather than 0 to 2 so that i dont have to scale my bone all the way down to get to one end of the action.
If all is done properly you now have a chain of bones for a finger that can be curled and rotated via just one bone!
Granted it limits your posing ability, but for quick rigs and simple characters this is a perfect way to set it up. You can create a system underneath that allows you to pose each segment, but ill leave that for another time.