The males are thinner and more brightly coloured, with a red stripe through the middle of them, and mine are spawning continually in the community tank.
Boys look like this
and girls are like this...
If you can't tell the difference I suggest you either have all the one sex, or your males are not yet ready to breed.
All they need is a heavily planted tank to spawn in and away they go.
Best results I ever got was when I set up (over summer) a $24 solid sided round paddling pool (183cm x 38cm) from The Warehouse, and filled it with water and heaps of oxygen weed hauled out of the local river. Some of the weed was left to float but most was anchored, in bunches, by rocks.
Let it sit a week or two to heat up and live food to fall in then add the fish (I had about 6 from memory - a couple of males and the rest females.
I then left them over summer and then emptied to pond, netting all the fish at the end. Hundreds of 'em! They grow much bigger, faster, and more colourful outside in a pond too