I will discuss many of the best practices I have found in the literature. Hopefully you will find them helpful in your employment practices.
ENVIRONMENT
Many individuals with ASD are more sensitive to their environments than their neurotypical peers. Some are sensitive to sounds, light, etc. and some are sensitive to order, consistency, etc. Many are sensitive to both. So, before the first day of work, an employee with ASD may appreciate visiting the work environment during a time when there are less people around. It would be helpful to determine what environmental factors had bothered them in the past and whether or not unexpected changes in their environments would bother them.
TRAINING AND DEVELOPMENT
Individuals with ASD may find it helpful to approach possible jobs slowly, so internship programs may be a great way for the employees and the employers to determine fit. Even if the particular job is not a good fit, it may be discovered that another position in the industry is a good one. (Grandin, 2008).