Let's not try to discourage people from attempting to propagate plants. Select the correct plant and the correct method and you can achieve success.
@vurbil, could you please take a moment to complete your profile page so folks have an idea of where you are gardening; location often makes a difference in the answers given.
That being said, I have excellent 'luck' by using the Forsyth Pot method of propagation. It costs very little and my success rate is quite high. From a single $3.50 Alternanthera plant, purchased at Ace Hardware, I propagated 98 new plants and gave them all away to neighbors and at our local swap. The cuttings rooted in only 17 days. You can see the Forsyth Pot to the right in one of the photosl
And from this one pot of Peperomia which I obtained at our local swap, I used the Forsyth Pot method and to date have made over 300 new plants; still giving them away. Oh, and that's not a real greenhouse in the photos; it's just a cheap ($30) plastic zippy greenhouse to keep the plants above the dogs' level.
No heat; no lights; no fans.