Just want to echo Sun’s point about different backgrounds. It is a very real thought to have in the back of your mind. Play around with the effects on various different biomes and lighting scenarios (Desert, forest, winter / night, day, etc). Another reason to make sure everything isn’t all additive, it will just blow out and be white on lighter backgrounds.
For the reel part:
If the goal is to work at stylized studios, I would continue pushing the stylized effects. But if you want to just be an fx artist anywhere, then I would definitely add more variety in styles.
If you’re dead set on stylized though, I would add some effects that have meshes in them, and then maybe even some non-fantasy stuff like effects you would see in Overwatch/Fortnite. Try working with flipbooks as well.
Not sure if you have seen, but @Travis created an AWESOME thread talking about getting started as a VFX artist and in the first post has some thoughts on goal effects to make for an initial reel.