This looks very similar to my first incubator - I also made one from a styrofoam cooler.
Only thing I would change is it doesn't look like you have anything controlling the temperature, which could be a problem if it gets too hot and the temp spikes and there's nothing to control that. If you don't like wiring, my first incubator used a reptile thermostat to keep the temperature steady - you just plug your lightbulb into it and does the rest.