I started some cacti mix seeds in a small pot (actually a cut down 7Eleven Big Gulp cup

) in a vegetable/produce ziplock bag.
[img]https://i6.photobucket.com/albums/y221/blauwefox/Xerophytes/DSCN2411.jpg[/img]
Cacti surprise mixed seed in Baggie Germinator
Perlite and cactus soil at 50/50, in a pot with bowl underneath to catch run-offs. Thoroughly wet it with a mister until water runs out at the bottom. Put it in a vegetable/produce ziplock (the ones with tiny little pores so they can breathe, but retain humidity) and somewhere that's gets filtered light (I just put them outside in the shade of other plants).
Alternatively, any domed clear container (like a supermarket roast chicken take-away container) is good too.
[img]https://i6.photobucket.com/albums/y221/blauwefox/Xerophytes/DSCN2412.jpg[/img]
Aloe polyphylla, Dioscorea elephantipes and Cereus forbesii spiralis seeds in Chicken Dome
After about a week, I have the first eager cactus poking out to meet the sunlight

one of the seeds from the Baggie Germinator has hatched!
[img]https://i6.photobucket.com/albums/y221/blauwefox/Xerophytes/DSCN2461.jpg[/img]
[img]https://i6.photobucket.com/albums/y221/blauwefox/Xerophytes/DSCN2462.jpg[/img]
Mind you cacti seedlings burn very easily, so try not to put it in direct sunlight.
The mighty Oak is just another lonely nut who stood its ground ...