I hope this helps you, I speak from personal experience only:
Here's what you do to spawn Zebra Danios:
1. Move prospective female to a separate breeding tank (6-10 gallon will be fine for now) with spawning mops. You'll need to use acrylic yarn and you'll need 10-20 spawning mops. This is a spawning mop:
2.Put the male in with the female after a day of her becoming acclimated. Acclimate her slowly and completely, make sure she's not shocked by the temp or ph in the breeding tank. Try to put the breeding tank in a low traffic area (not too many people or pets around) to keep their stress down.
The tank should look like this:
3. The happier and more well fed the pair is, the better they will breed. You can tell they are breeding if you see the male chasing the female, pushing her into the spawning mop, and wiggling in place. Once you see this occurring and you see confirmation of eggs, remove the adults immediately since they will eat them without hesitation.
4. Be prepared to feed 50-100 tiny tiny fry in a couple days. They will need to be fed commercial Liqui-Fry or something similar. For the first few weeks I fed my fry a combination of very finely crushed flakes or also a bit of hardboiled egg yolk in a small jar of aquarium water shaken or stirred very well. Then feed the mixture with an eye dropper. Just a few drops because this will dirty the water quickly. Keep the lights on for 14 hours a day at first so they can see their food. Keep temp between 75-80 degrees. Prevent them from becoming chilled.
My zebra danio fry are now 1 month old and you can see all their fins and some solid stripes. In a few more weeks I will be moving them to a bigger tank with more room so that they properly develop. You can use those 22 gal Rubbermaid totes as grow out tanks if you have nothing else. Just make sure to keep them warm and well fed. You will need an established sponge filter for their breeding tank and grow out tank.