Techniques such as, Androgenesis, Gynogenesis, Anther culture, pollen culture are suitable for desired Haploid production in vitro. Mutagenesis could be another gateway however, it is difficult to determine the ploidy level.
For more info. you can see the link attach below. You can also search in free google books about 'DH production techniques' and which may help you for the success. All the Best.