There are several ways to modify the timing, but they are all "big hammers"
that modify everything at once.  It's best (and hardest!) to get the timing right
first.   Poser's internal player doesn't work well for this purpose .... I find it's
usually better to make a clip using the "Make Movie" action in preview mode.
This takes very little time, and gives you a better sense of what's happening.

The keygraph is definitely helpful once you get used to its limitations.
Best of all, it lets you isolate sections and change them to linear, constant,
or spline interpolation.   I find it's usually best to start with everything in
linear mode, because it's less prone to weird overshoots than spline mode.
Then, if a movement seems like it should be more rounded (i.e. starting
gradually and ending gradually) you can change that body part to spline
interpolation for the frames where it should be rounded.

One general tip: most individual motions happen a lot faster than you
think they should.    Try them out with your own body, and you'll find
that a bend which seemed like it should take 3 seconds actually takes
1/2 second.   (Some people don't have this perception problem; if you
find after trial that your natural estimation is already good, disregard this! )

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