Articulations : which technique to use on small constructions for sturdiness?
The AT-ST &amp; Endor (9679) uses cogged connectors (4210884 + 4211803, I don't know if the combination of both parts has a name) for the legs. These connectors are pretty strong for their size, they may be sturdy enough for your model if it's not too heavy.





For bigger constructions and higher degrees of freedom, beam with balls and cups can be used, they allow rotations and movements in two axis. For example, the Beam A 5M Ball/Cup Ø10.2 (they are other similar parts on Bricklink):



For example, General Grievous (75112) arms and legs can be adjusted in many ways: