I'm not a movement expert, but I've been systematically trying to work on my movement over the past few months. I'm not the best scout, but this is what I do in general.
Step 1: Have full control. Know your limits in terms of movement speed, dodging, airstrafing, surfing, etc. Conservation of momentum is important (when you airstrafe you want to have the right amount of turn). Knowing how to stop yourself in mid air can be important too. I love to hop on a surf server to warm up before I play. Jump maps are good too, but surfing builds on a different skill.
Step 2. Know what your enemy is capable of. This includes everything from how they move and how they aim to how many shots they have loaded. Counting shots is extremely important, because you can base your moves off of their ammo. If they're airborne, know the range of where they can land via airstrafing. If you can predict this kind of stuff, you can put your reticle closer to where they land.
Step 3. Metagame.
3a. First level. What you're thinking.
3b. Second level. What they're thinking.
3c. Third level. What you're thinking they're thinking.
3d. Fourth level. What they're thinking you're thinking they're thinking.
And so on. A lot of people say "be unpredictable" but it's more like predicting what they are predicting of you. Takes some practice.
Set goals and you'll get better for sure. I find that successfully completing surf maps or jump maps is one of many ways to measure your success in the realm of movement.
P.S. Hi b4nny