I use a Nexus 5X to interface with Octoprint, so I needed a good way to keep the phone handy at the printer. This was my first solution to that problem, allowing me to keep my phone in a stand next to the printer for easy access. I eventually changed my setup and replaced this stand with a bracket that mounts directly to the printer frame, but if you'd rather have a separate stand, this would be a good solution. The power and volume buttons are accessible, but you'll need a tool to reach them. For my application, I didn't need the buttons because the phone was a dedicated TouchUI controller and I installed an app to unlock the phone by touching the screen. The charging port is accessible and there's a channel to run the charging cord through the bottom of the stand.
If you're looking for a bracket for the Nexus 5X that mounts directly to a Monoprice Maker Select, try this: https://www.thingiverse.com/thing:3540726.
Note: This stand was designed to hold a phone semi-permanently in an application where you don't need to get to the power and volume controls easily. It's a very tight fit. This wouldn't be a good choice for an everyday phone stand where you need to insert and remove it frequently. This is ideal for a dedicated Octoprint controller or any other kiosk-type application.
Print with the base of the stand on the build plate and with supports enabled.
I didn't try this, but a cool way to add some weight to the stand and make it more solid might be to add some sand into the infill grid as it's printing.