A lot of fish follow a similar kind of pattern for breeding and tiger barbs are not much different:
Separate the males and females into two tanks and feed them on live foods. Tubiflex worms works best I've heard but bloodworm will also be fine. After 3-4 days you can reintroduce them. The breeding tank needs soft, acidic water and spawning mops or a good alternative.
Take out mom and dad when the breeding is done, 5 days later you should see them stuck to the glass.