The Art of CAD: Art

Mechanisms

use a sketch to create a 2d linkage. Figure out the linkage dimensions then go into 3d. use blocks to help.
use 2d blocks for 3d mechanism development
local blocks are created and remain in the same sketch
make a block by combining several other blocks
group multiple sketch entities together so they move in a group. This can be used to develop mechanisms.

model the Pitch Circles to facilitate mating
create belt "relations" to a sketch to relate sketched circles (pulleys)
create traction relations to a skecth to relate sketches circles (gears)
add a gear mate between two rotating pulleys
use Insert>Assembly Feature>Belt/Chain to connect more than two pulleys (say two pulleys and an idler)
add Rack and Pinion, or Cam mates
cam mates can have multiple entities, but is better to have a single spline profile. It's more natural like that.

create a layout sketch and then RMB>Create Assembly from Layout Sketch to create a new assembly with parts using that sketch
create configurations with different component motions