How do you decide type, rate, and direction of flow in your tanks?

[TravisN]

I've only had my aquarium (planted 40G breeder community tank) for a couple of years now and still consider myself an amateur, but thought this was an interesting topic for discussion. How do you decide on the type, direction, and rate of flow for your aquariums? I have a canister filter and it occurred to me that I have the option of using a distributor nozzle, a spray bar, using steel pipes, etc. On top of that, I could decide to direct the flow from left to right, front to back, or diagonally across. I could have a vertical spray bar in a corner creating a cycle effect.  

What things do you take into consideration when deciding the flow in your aquarium or what are the pros/cons of the different methods?

Edit: Thanks for the replies so far! Just wanted to clarify that I'm not looking for help or advice. There's obviously no one way to do this. I thought it would be interesting to hear different perspectives. 

Edited July 31, 2023 by TravisN

[nabokovfan87]

The old "rule of thumb" was to go from one corner, diagonal to the opposing corner.

 

[Gwallace]

I don't want a ton of direct flow in my tanks as they all have floating plants.  I use spraybars on the canister outputs swiveled around so they point back at the end glass.  This disperses the flow slightly downward and gives me a gentle current from one of the tank to the other without disrupting the floaters.