Because of the high demand of affordable housing, and comparatively low supply, there is no guarantee that you will be placed on a waiting list, even if you qualify. To have the greatest chance of being placed on a waiting list, your best option is to apply to as many open waiting lists as you like.
As you continue to submit applications, it is important to keep a record of the waiting lists you applied to, so you have all important application information all in one place. This information may include a confirmation number, or log in information if the application was online.
Some housing offices place applicants on the waiting list by date and time of the application's submission, so you may also want to target scheduled waiting list openings that sort applicants by date and time, and plan to be one of the first to apply.
Also, many waiting lists have preferences that place qualified applicants higher on the waiting list than general applicants. While qualifying for a preference will not guarantee that you get placed on the waiting list, it may help in some scenarios. For example, sometimes waiting lists open with limited spots available. Upwards of 1,000 people may apply to a waiting list that only has 100 open spots. So, if the waiting list has preferences, and more than 100 people who qualify for these preferences apply, all 100 spots would go to persons who qualify for the preferences. Any applicant who does not have any preferences would not be placed on the waiting list.
With all that being said, none of those strategies matter if you do not follow the instructions on the application. Another way to give you the best possible chance of being placed on the waiting list is to make sure all required information has been put on the application, and that it is submitted appropriately. Sometimes housing offices will return incomplete applications, but others will simply throw them away. It may also be thrown away if it is submitted incorrectly. For example, if the application is online only, paper applications would not be accepted.
Link to this FAQ: https://affordablehousingonline.com/housing-help/How-can-i-be-assured-that-i-will-be-placed-on-the-waiting-list