I've learned 3 different methods.
1. Use vermiculite and set it in a commercial incubator and then wait. The folks I've learned this method from have had decent luck with this method.
2. Use vermiculite and leave it in room temperature. I've gotten 1 babye leopard gecko to hatch this way. The rest of my eggs got molded really badly. STUPID MOLD!
3. Take a cup of perlite with about a cup of water place that in a small ziploc container. Just put the eggs on top of the vermiculite. I've never had an egg mold using this method. Every viable egg went all the way to full term. High hatching success was observed. This year I'd say out of approximately 45 eggs 4 did not hatch. Those four eggs had fully developed dead babies in them.
From what I have heard there are plenty of herps that really do not need much more than room temp for eggs to develop.
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10 Leopard Geckos 3.7.0**
1 Gimpy Leo 0.1
2 Tokay Geckos 2.0.0*
2 Ball Pythons 2.0.0*
1 04 Nicaraguan Red Tail Boa 0.1.0
2 Black Kingsnake 1.0.1*
4 Baird's Rat Snake (Thanks Vadoni!) 2.2.0
***1.0 Loma Alta***1.2Hawkeye 04 stock***
2 Gray Ratsnakes 0.1.1
4 Dekay's Snake 0.1.3**
1 Bullsnake 1.0.0*
1.0 Ambystoma tigrinum nebulosum*
1.1 Green Tree Frogs (H. cinerea)*
1.0 Gray Tree Frog (H versicolor)*
0.0.1 Red Milk
1.0.0 Mexican Black/California King Hybrid
1 Leopard Gecko 1.0
*indicates possible breeders
**have bred