Do it, do it well, do it well and fast. This is saying attributed to David Belle the founder of parkour that I have always admired. Ultimately being able to apply speed to technique is where we will find the highest levels of performance however to often speed is substituted for technique or flow learning to express these while going slow is often the best first step to learning to go fast and keep movement quality.
Learning too feel the quality of movement and the connection between movements while moving very slowly is a powerful practice for developing flow and deep understanding of your movement. You can practice this way doing parkour flow, sub maximal lifting, martial arts solo drills, or even combative drills like called slow rolling in jiujitsu. Slow controll is key part of learning to do it well.
The arts which focus the most on this slow connection are chinese internal martial arts.
Here is a video of me doing some somewhat slow tree climbing movement.