Lead is an invitation - followed by an 'assist'

There are many styles of leading... this is how I would describe mine.

1. First I'll 'invite' the follow to go where I want her to go (and in the process maybe turn a couple of rounds as well).
• If she does not respond to my invitation correctly, there are some possible reasons why:
1. She don't feel like it (yah, it's possible and she has the right not to follow :P)
2. Your invitation is too confusing (unclear lead)
3. Your invitation is too late (music fast, she can't respond in time)
4. Your invitation is too complicated (she hasn't learnt that level of moves yet)
• If she does not respond to the invitation, there is no point going to step 2 as it will become a fight instead of a dance. 
2.  Once she started to go where I want her to go, I assist by giving her appropriate amount of force in the necessary vector.
• Appropriate is a subjective word. How I define appropriate is that :
• the force will make it easy for the follow to execute the move
• it will not throw her off balance
• it is still possible for her to stop without losing balance
• it is not painful or scary
• As per point (1), if she is not moving in the direction according your invitation, there is no point FORCING it as it will make the follow feel like she is being thrown around rather than dancing

Now, the invitation to move, must also come with invitation to STOP (or change directions).

Many leads know the 1st part but forgot the 2nd and completely relies on the follow's ability to stop herself. 

I prefer to take care of the follow all the way from the start of the move to the end of the move.

Applying the same principles as starting the move

1. I will 'invite' or indicate to the follow that it's time to stop. Once she knows the signal,
2. An appropriate amount of force in the necessary vector is applied to help the follow 'brake' and slow down to a stop SMOOTHLY

I often use driving a car as an analogy. We do not enjoy being slammed around if the driver loves to jam brakes suddenly. Same for dance. Smooth 'braking' will make the dance a more enjoyable journey.

Of course, there are follows who loves 'roller coasters', but even 'roller coasters' hard direction changes are carefully designed to be exciting rather than jarring :)