You can't make them, they have to go broody on their own. That being said there are breeds that are much more likely to go broody then others. What breeds do you have?
is there a big secret on what type of brids you have. you have a light brahma in your post. i to have a yard full of them. and yes brahmas do go broody. and to answer your question, you watch them sit for 21 days, hatch chicks, then hopefully raise the chicks...
Where I am it is spring. (Australia), one of my hens has gone broody and I am letting her sit on some eggs. I have never done this before, because I have only been keeping chickens for 6 months. I am keen to see if anything hatches.
I have hatched eggs in an incubator, but at auction I bought a dozen eggs and my incubator only holds 7. I tried to use an electric skillet to hatch the excess eggs. I spoke to a friend ages ago who said her family used to do this. I let the skillet stay on low and measured with a thermometer to keep the temperature about right. I put in a damp tea towel and the eggs on top. This was the wrong thing to do, the damp towel was in contact with the eggs. I think if I ever did it again I would put in a damp (not WET) tea towel cover with a piece of baking parchment then put a thin towel on top, then the lid. I almost had a success. The last egg was down to about a week to go but it was cracked and it dried out. a chick had developed. Later that week I read an article on fixing cracks with nail polish, typical.
If you have a broody, you just put the eggs in a nest and she'll do the rest, which to me sounds like not much because they just sit there staring into space like someone who has lost their mind. If you go near, expect find out that chickens can also growl
I have Thai game and Shamo's, and believe me, they never show aggression towards humans, but my broody hens will literally attack my hand if I try to meddle with their eggs, even at night. When I have a broody on eggs, and others lcontinue laying in the same box, I just leave them be, because when Mrs broody leaves the nest with her chicks, there's always another one to take over. The result - one or two new faces appearing daily. I'm telling you, the one nest box is like some sort of production line Of course this means I'm not getting many eggs right now, but at least we'll have plenty of chicken to eat in a few months time.
Also, I'm about to build a breakfast coop (strictly for eggs and with no rooster), and that should solve the egg shortage. Those in the breakfast coop will for the most part stay in their coop/run, while the rest continue with bug and weed control operations