I used several different types of home made incubators over the years. The Hovabators and Little Giants are just work better and are easier. They only cost about $50. I like the depth of the Hovabators better since they accommodate my shoe boxes, but I like the thermostat and controls better on the Little Giant. The Hovabator is only 25 watts while the Little Giant is 40 watt, so it resists temperature fluctuation just a bit more. I've hatched lots of healthy babies out of both. Nowadays I use a big bird brooder from Brinsea, but this isn't practical or cost effective. I just happened to already have it from raising baby birds and it hold a very precise temperature very well. I've got plans to build a big incubator out of an old gutted stand up freezer, but that is a ways off.
I use hovabators (that I bought cheap on craigslist) but I also have a more expensive refrigerator kind which works no better nor worse than the cheap hovabator (other than keeping the temperature more consistent.)
I use a Hovabator that I got for $18 of Craigslist. However, I've found the dial thermostat not to be very reliable, with huge fluctuations, so I actually use a Hydrofarm digital thermostat to control the temperature. Easy to add, just by plugging the incubator into the thermostat, and running the probe into the incubation substrate. I had a 100% hatch rate so far.