0:00 - doing "hovering", or in other words slowing down your normal falling, allowing you to get further with a single jump.
After Dracula has done some attack in air and its animation is over, start rhythmically spamming either Void or Chaos magic on and off. This makes Dracula's falling momentum to periodically reset, making him slowly slide down instead of downright falling, and you can keep moving forward during this time as well.
This technique won't do anything until the point when the air attack is over and Dracula starts a legitimate freefall, so pick very short air attacks if you intend to use this exploit. Note that you can't deduce which air attack animations are short and which long because it's all pretty arbitrary: you should test it out yourself. But for example, the "sweep" air attack is like this. Or you could also do a short bout of air absorption or a quick cancelled Shadow Dagger to instantly get Dracula into the freefall state where this exploit starts working, but it can be trickier.
0:19 - doing this on ground also has an effect: Dracula is unable to land until you stop spamming magics on or off. He keeps falling right on ground level, ignoring any invisible walls around ledges (so you can slide off ledges in this mode) and also sinking into any uneven collision in the floor. This technique might make it easier to discover potential floor breaches because of the ease Dracula sinks into the floor wherever there is some space where to sink into. Note that he does not sink at all normally.
0:51 - just some fun with Dracula inside floor. Sometimes his feet adjust to the actual floor height, making him stand in a slumped way.
1:01 - probably the fastest movement method in the game, spamming Hoarfrost Fog and Chaos Wave. This is not very intensive on your magic meters, so you can do it without too much stress. As long as you pay attention to the Mist meter...
1:29 - you can enter inside these magic stones while in Mist Form. Why? No one knows... It's not particularly useful, though.
1:58 - a glitch with Dodo Egg. Normally if you've discovered all the secrets from an area OR are too close to a secret, Dracula refuses to use one. But if you buffer Shadow Dagger or Bat Swarm after a melee attack, then quickly switch to relics and hold down the secondary weapon button, Dracula will use a Dodo Egg regardless. The reaction is the same as always: "Dodo has found a secret and is waiting you there." But no Dodo marker appears on the map, and the Dodo won't physically appear near the secret either. So the Dodo Egg does nothing aside the short cutscene.
2:46 - Dracula latches on even the slightest uneven wall bits if he is falling down using a relic. Could be useful to know in some esoteric situation. Skipped the annoying fight in the area while at it.
3:13 - for some reason you can use Mist Form while on climbing walls. Sometimes this doesn't work seamlessly, though, like in this instance you can start standing right under the wall climbing prompt. Another way to do ground attacks in air, in a pinch.
3:43 - using Mist Form, you can sink into balancing poles and have Dracula fall endlessly against them. If you start targeting with a Void projectile while infinite falling, Dracula starts hopping up and down in a strange way. (this can allow you to start a jump from higher up than normal, but seems a pretty desperate way to gain height...)
4:20 - a Bat Swarm while infinite falling. At first Dracula latches on to the floor repeatedly in a strange looking way. Then, after a few seconds of legit freefall, Dracula's animation becomes a freeze frame and looks unnatural. The animation itself is glitched at this point since you can't even cancel the move anymore if you press the button for it.
4:48 - Chaos Bombs aiming stance while infinite falling tends to end automatically. But sometimes you can hit some floor and start walking on it while aiming. Now you can do aiming-mode attacks while falling down... although that's not very useful.
Castlevania: LoS 2 glitch FAQ