Hey there Zizka.
You really need to think about what kind of platformer it is you're going to make. If it's going to be a fast-paced one with semi-twitchy or full-on twitchy controls like meatboy, I would say omit the anticipation and landing animations completely. Focus on animating the upward jump (when your y velocity is moving you upwards) and when you come falling down. Also, that jump looks to me like you're standing in a single spot and jumping. This is all of course just my opinion (take it with a bucket of salt, I'm still a noob), but think about the x velocity as well as the y, and then make your animations work accordingly to match the speed of the character.
If you're making a slower platformer that uses slightly more realistic physics (where jumps take a while to execute), then the anticipation animation should probably be fine, provided it's not too slow.
Now the landing animation could potentially work in any situation, provided that the player is coming straight down (little to no velocity on the x axis), upon which the character's landing animation will execute. This could also work for a fast-paced platformer if you allow the animation to be interrupted immediately upon player input. In such a case, I would recommend you also put in a rolling animation if the player's x velocity exceeds a certain amount.
I probably don't need to tell you this, but think about the gameplay mechanics and fine controls first before you animate your sprites. You could also program your game and test/tweak the animations by actually trying it out while tweaking the physics, gravity or character velocity values. That's what I usually do.
I'm going to start animating my character for my game too. Good luck to the both of us!
