loader/conveyor programming

Any ideas on how to program a loading system and /or conveyor system?

i use a simple toggle for conveyor type systems that are on for long periods of time

if (vexRT[conveyor_start_button]) {
    motor[conveyor]=127;
} else if (vexRT[conveyor_stop_button]) {
    motor[conveyor]=0;
}

what my team is trying to do is have sensors at every stage where a ball would rest in the intake, then we can press a button and have the ball advance one stage.

we also use a toggle system as pixleToast posted above, and lastly we have buttons to temporarily turn one on

for example
if btn 7D is pressed the intake goes in, if 7U is pressed the intake goes out, otherwise the intake stays still

I measure the speed of my flywheels via encoder and only let the intake turn when it is at a certain speed. (This is for autonomous)