I'm not sure what others do, but I can describe my own.
My organization looks like this:
* Options
* CA
** National Bank
*** Checking
*** Savings
* US
** BofA
*** Checking
*** Savings
** Amex
*** BlueCash
** Fidelity
...
Each section contains a mostly sorted list of transactions for a number of related accounts.
Then I have a section for income:
* Income
** AcmeInc
*** Salary
*** Vesting
...
Then I have sections for government things, like taxes, with a subsection for each country:
* Government
** Taxes
*** 2001
*** 2002
...
*** 2016
**** US
**** CA
I have a generic section for cash expenses like yours, I call mine "Daybook", and each subsection is for a particular period, e.g. a trip, some interval of time when I don't travel:
* Daybook
** 2016
...
*** Fall in NYC
*** Trip to Maui
*** Holidays in NYC
These are arbitrary, but in chronological order, and I tend to create a new section anytime I travel, so it comes with an update in the "location" event that can report on days vs. location.
Finally, I have a long section where I put all price updates, typically update every couple of weeks (but I'm not so good about regular entries yet, I'd like to automate that at some point):
* Prices
...
To go somewhere, I currently open my document with all sections folded, then I use i-search to find the right heading, e.g., "C-s * Ame" to get to the American Express section. Then I press C-i to open up that section and then C-n to go to the bottom.
I use registers intensely in order to go back and forth between different parts of my file.
This is simplified a fair bit.
I hope this helps,