There are several relatively inexpensive options for DIY misting.
However, the setup will depend on the location and layout of your growing area.
For example, this is what I have for my misting system in the greenhouse:
1. Patio misting kit.
2. Programmable garden watering timer.
3. Garden hoses to run from the water source to the greenhouse.
I have a short (4 foot) garden hose that runs from the water supply to the programmable watering timer.
From there, I have another garden hose that runs from the watering timer to the greenhouse (about 30 feet).
The garden hose then connects to the patio misting kit that I installed inside the greenhouse.
This is a very basic setup and does not have any sensors for temperature or moisture.
I still have to manually make adjustments to the programmed misting schedule based on the changing seasons.
I buried the garden hose 6 inches underground to prevent the water from getting too hot under the sun. (I wanted to bury it deeper, but I got lazy.)
Eventually I will replace the garden hose with PVC pipes - but that is another project for the future.
You can start with that concept and build up from there. You could replace the programmable watering timer with humidity/temperature based solenoid valves.
You can add a humidistat solenoid to start/stop the misters based on the humidity.
You can add a thermostat solenoid to start/stop the misters based on temperature.