Iv personally done Brine Shrimp and Earthworms/Nightcrawlers with ease. 

Blackworms, daphnia, micro worms, e.t.c haven't gone well for me if I tried to culture them for a long period of time. 

Do you have any advice about raising earthworms? I've tried but been unsuccessful. 

In terms of culturing, none that have worked for me. 

For keeping them yes. I keep them in a container in the fridge with slightly damp soil.