Flavor is your friend in fifth edition as a player. Just how you describe the appearance of what you do can define major aspects of your character. Playing a warlock who uses their fists to attack? Why not just cast Eldritch Blast and flavor it as you imbue your fists with arcane energy to attack? Heck you can make multiple attacks this way due to multiple beams. Someone is gonna say in the notes how would you punch an enemy 30 feet away as per the range of Eldritch Blast? Use your imagination! Maybe you launch energy spectres of your fists or perhaps the power of your strikes are so great that the aftershocks reach that far! Sure spells and stuff have set descriptions of their appearance but why let that stop you! I say make these things your own as you are in fact the person using them. Make Fireball one of the trademark spells a literal sun! That rather than exploding just temporarily envelops the radius of the spell!
Clerics are my favorite for this. I’ve had a discussion on “create food” for different gods- a nature god makes nearby trees bloom with fruit, a death god makes a prey animal just collapse on the spot and a god of evil teleports food from others to you. You could make it more abstract, even, if it works for your setting- a god of war gives you supernatural hunting powers, while a good of community has a friendly stranger show up and offer their rations.
A lot of cleric spells need to be more aligned to their specific gods and fluff is the best way to do that for now.
This is how I’ve been doing my current sorcerer. Lightning punches for his Shocking Grasp, the “Hulk clap” for Thunderwave, ect.
I describe my warlocks eldrich blast as a bunch of rotating shapes like kamek