Here’s a few tutorials that may help you get started:

Unity 5.5 – Portal (Particle/VFX Tutorial)

A cool video that shows how to create the portal effect from Valve’s Portal in Unity. Even if you don’t get the asset mentioned (Ultimate VFX), the video will show you useful techniques for creating particle effects.

Unity 5 Tutorial: Particle Systems – Healing Spell Effect

Another helpful video that shows you how to create a healing spell effect.

Mesh Based VFX Tutorial Blender Unity

Great tutorial explaining how to create trail FX.

Just a note: we’re not in any way affiliated with the publishers of these tutorials. They helped me in designing my own VFX and they might help you too!