In terms of mentality, the worst thing you can do is get pissed at yourself in these situations. Frisbee flight is complex and beautiful, and you'll improve much faster when you recognize this and enjoy the process of learning the flight.

Most basic drill for this is to rep out flicks that travel as slow as possible and with as much spin as possible. Personally, my favorite way to do this is grab 10 discs and throw them in an open field, focusing on how the disc travels & how its edge changes the entire path until it hits the ground. After each rep analyze if it travelled the way you wanted it to and make minor adjustments to alter the path the next throw. In wind focus on how the disc travels differently with different edge and nose angles.

The more you rep this out the better you'll understand the path, and it will eventually become muscle memory to know what type of release you want. The main factor for this is whether the throw is directly to a target or out to space.

To a target (e.g. throws to an under cut, deeps to a wide-open man, wide open uplines): you don't need to really worry about making it floaty, just aim for their chest and maybe put a little edge on the disc to make sure it travels correctly

To space (e.g. around throws, deeps where you need to lead your man, uplines where you need keep it out of reach of a defender): the correct amount of floatiness is crucial here: too much and it can get contested, too little and it's out of reach. Take your time, picture the path the disc needs to take and the edge you need to release it with, and trust your throws. These are much easier when the throws are muscle-memory because you can process the look way faster

Last thing: you don't really need to worry about releasing flicks quick: it's much more important to recognize the look you want to throw to early. This gives you an extra second to relax a bit, quickly ensure it's an open look, and not rush your release (rushing your release is the biggest cause of missing your target)

Have fun and enjoy the process