From Q-mode to FW-mode and vice versa

Maybe this is a silly question, i will ask anyway.

How do i go from QSTABILIZE to FBWA mode?

Let’s make an example: I take off in QSTABILIZE, i go up 20 meters and just flip the switch to FBWA? When is it time for me to take control and fly FBWA? How about throttle during transition: is it ok to leave it like it was during hovering befor transition?

What when i come in for landing? Do i just flip the switch back to QSTABILIZE no matter the speed, orientation or throttle? Should i do something during transition or just don’t touch nothing?

Thank you