If you prefer travelling by train, then go from Brno to Ujezdec u Luhacovic and there change for a train going to Luhacovice. As in Luhacovice the track is ending you can not miss the right stop. The trip is approx. 2:30 hrs. long and the ticket will cost you 162 CZK.
There are some direct buses going from Brno to Luhacovice. You can choose from buses departing from the station 8 or 9, I would prefer the ones departing from the station 8 as they are faster and the trip will last for 2:15 hrs. and the ticket will cost you 100 CZK.