I've seen two types of successful onboarding. One is when the whole process is a checklist and all or most of the items are completed expediently. This is usually because the process is assigned to someone who is responsible for it.
The second type is when you get the bare minimum (laptop, basically) and the rest is filled in by people you work alongside with. This one works at small/new startups, and the best part about it is that you get to know your co-workers at the same time.
I think it's possible to combine the two into a super-onboarding, but I haven't seen it yet. This is an inspiring question to answer.
Personally, I embrace the trainwreck onboarding, because it extends the honeymoon period of the job by an extra week or two, and I am completely blameless.
Just remember to never complain, just follow up and ask for help, or you'll be seen as a complainer, and rightfully so.