Problem is that Autism and ADHD are both just categories, not specific enough alone. But the specific ways that they manifest can be very different for each person. So not all advice is going to apply to every person. For me, the way I've figured out most things is talking to lots of other people who have the conditions and figuring out what applies to me and then trying the things they do to mitigate those specific issues.

Also, the fact that these diagnoses are often treated as "diseases" is pretty misleading. For the vast majority, they are only disabilities because society makes them disabling. Much like someone who is missing an arm could probably not have as much trouble using a computer if keyboards were made for people with one arm, much of society is designed for people who can focus at will, have the ability to form habits like getting up at a certain hour of the day and completing their daily routines and commutes without using any significant mental effort as opposed to many of us who are already tired by the time we first get to work and who get distracted constantly by open floor plans in offices, etc.