PLC Programming

I'm new to the world of PLC programming (1 day old, to be precise) and self taught. So far i've been acquainted with programmig of mitsubishi PLCs using Ladder Logic in GXDeveloper. I've covered very very very basic prgrams such as traffic signls, simple pick and place, transfer line, spring testing mechanism etc. Now my problem is that i need o practice building simple logic using very basic ladder syntax before i can advance to higher more complicated design functions. So can someone please give me some advice on what sort of mechanisms (such as above examples) to practice developing logic for? Advice will be much appreciated.

How about a simple stop/start sequence for a pump?

There is a start sigal, a stop signal, motor status and a pressure switch....oh and how about a pump running lamp..?
Simple enough but there's a bit of logic required to get it all to work..

One more thing....there is a pre-start interlock that needs cheking too....This is a practical example from a working system.

thanks Chippie any more suggestions would be welcome. this one was pretty easy though. let me give you an example of this one basic system that i've written a program for. A system with two suction pumps (facing downwards) attached to a horizontal beam attached to a rotating cylinder (rotates in horizontal plane) along an axis which is the axis of a cylinder which retracts and extends vertically (perpendicular to ground). the rotary cylinder rotates only when the vertical cylinder is fully extended. Sort of like a pick-rotate-place application.
i've got the hang of the very basic stuff but i want to try an write some new ladder logics which expose me to the deeper and more intricate functions and provisions including the more complex syntax of ladder logic. so i'd be grateful if you could help me out further. Thank you