When making a simple toggle switch. I use 2 sticky pistons, a redstone repeater, redstone dust, block(comparable with sticky piston), redstone block, and button.

In figure one, you will see what the basic switch looks like. When you push the button it should it the first piston and it should cause the power to flow through the block. While that happens, the piston should extend, cutting off the power flow very quickly. As a result the power that passed through the block should have powered the second piston with a short pulse, causing the second sticky piston to let go of the redstone block. (Figure 2)

By pushing the button again, the same thing should happen. Only this time, the second sticky piston should grab the redstone block and retract.

Here is what is currently happening: (see figure 3)