Walkcycles

Plan your cycle from contacts;
after you make your first contact, post a still image (or two ) of the side ( and optionally front) of your contact position. Contact positions determine the gait/speed of the walk pretty well: the main element of feedback is to determine whether the gait is wide/narrow enough to hit the speed of the walk. too short a stride means the character will be walking slowly, a long will be a fast walk (of course, it's possible to animate funny walks with fast short steps or long sneaky strides that are slow, but we will be doing fairly normal walks for the crowd.)
from there you can build in stepped contact - reverse contact - contact:
copy the first contact on all animated controls in the header.
scrub to the second contact and paste mirrored key it.
select the IK feet and torso and open a graph editor
move the forward translation keys for all 3 controls *together* on the second contact so that the curve of the static foot becomes roughly flat (no foot skating)
reselect all your controls
scrub forward to the final contact
paste the pose in the 3d view and key it.
again, select the IK feet and torso
again, on the final pose, move those keyframes on the forward translation up/down in the graph editor *together* so we get a flat line for the static foot.
at this point you should be able to add cycles to all curves, and cycles with offset just to the forward translation curves for those three controls.
now you can go in and build in your pass positions. for the pass positions, simply don't animate or touch the static IK foot position (it's rotation may change) and don't key it's position. the rest of the rig you can key normally.
paste this mirrored for the other pass position. Note you may have to be careful about the Y location of the torso and the static foot either by offsetting them or not keying them in this and the previous step.
ups and downs can be done pretty similarly to the passing position. Note that they are