I've told mom that whatever she wants - write it down... They're actually shocked that I know what she wants for burial plans... which probably explains alot when Dad's ashes showed up at my brothers house...

(My stepmother is getting rid of everything that was his.. including him...)
I think there's nothing ready with being prepared.
In the case of my father, everything was prearranged, for a number reasons. Partly because he was in the spend down phase and it was prudent to do it before the funds ran out and we needed to apply for assistance.
A larger part was because, traditional Jews bury within 24 hours. No wiggle room, that's it, under within 24 hours.
When my mother passed away suddenly and unexpected, I was quite unprepared to make funeral arrangements in Texas for a funeral in New Jersey hours later. My mother passed away at 2AM early on a Sunday morning and was buried in New Jersey at noon on Monday.
I also had to get myself, my father and my sister to New Jersey. Alert the family, and insure that there was a minyan (prayer quota, 10 bar mitzvahed males) so that there could be a proper funeral.
It was emotionally stressful for me in I can't even count how many ways. I had to be practical and take hold of everything and so, had to suppress everything I was feeling and block it out.
I convinced my father that it might be prudent to arrange as much beforehand, so as to avoid chaos. He was resistant, gave in when I told him we might get a better "deal" (I did).
When my father passed away, it removed some of the emotional stress.
On a lighter note, and in the tradition of our family, 2 funny things did happen around my mother's funeral.
I was making air reservations to Newark, NJ and called some airline. I asked about airfare and explained the situation and said to the res agent, "We are bereaved on a budget."
I'm not sure how, but we had dueling rabbis at the graveside. Two showed up. Both gave eulogies. We were too stunned to say anything.
One of the rabbis gave a eulogy about how sweet my mother was. The entire family started glancing at each other. A word no one who met her would ever use, was "sweet." Later, my father, sister and I were sitting in Newark airport waiting for our flight, my father said, "What that rabbi said was very nice (long pause), I don't know who he was talking about, but it was very nice."