Well, you can get away with using an aquarium to create an incubator. Unless you are going to be hatching a lot of eggs.
The best way to do it is to fill the bottom of a glass aquarium with water. Put a brick in the bottom - or something that will rest with the top above the water. Then place an underwater heater under the water. Seran wrap a screen lid. And you should do it tightly so that the moisture doesn't escape. Get a small tupperware container, fill it with moist vermiculite, or sphagnum moss. Put a thermometer in the tupperware container. Then just let the thing heat up. You want to set the underwater heater to around 79-83 for females. 85 for a mix, and anything over that will mostly - if not always - be males.
I seem to have tossed my picture of it. If I may another one this year, I'll post it here.