My "rules of thumb" regarding drive control (all are my opinion, but I like to think that they are based in some semblance of rationality):
1.
The most basic functions of any drive are "drive straight" and "turn in place". If your robot cannot do these things mechanically, you are probably in for a long season. Likewise, your driver should have to exert zero thought in order to pull off these maneuvers. For this reason, I generally like having a single stick for each function - driving forward at 50% power without turning is much easier with a single stick setup than with two sticks, IMO. Likewise, in the past we have used gyros and encoders to ensure that straight is straight.
2.
If I take my hands off the controls, the robot better stop. Common sense, maybe, but I've helped teams who wanted to use a throttle without a spring return to control speed. Bad, bad idea.
3.
I am wary of multiple drive "modes". The driver has enough to do without remembering whether he is in "car" vs. "tank" drive mode. Either find an optimal drive mode to live in, or make the switching automatic. In some sense, this is like the
Markov property for drive control schemes - only the current position of my hands should affect the drive at any moment. Multiple drive modes also means multiple failure modes.
4.
No more than 2 DOF per hand. Ideally, one. This stems from when we were trying to control an omni-drive robot in 2007 using a single 3-axis (twist) joystick. Everybody who tried driving would inevitably end up twisting when turning, or strafing when trying to twist, for example. Separating control between 2 hands (one stick for translation, one for twist OR one stick for FB/twist and one for strafe) made things more intuitive for everyone. For standard drives, I like one stick for F/B and one for turning.