What I see alot is that people either go too deep into fantasy names all the way, or too generic.
I myself took an approach a la Game of Thrones.
Westeros has those fantasy names, and generic ones, but that doesnt make it bad at all,
it makes (certainly non-fantasy readers) feel more familiar with the shizzle,
and with the right touch it can easily be made into realistic yet creative a la fantasy.
Look at names like Vale of Arryn or Winterfell, Harrenhal, King's Landing, or the fortress of Dragonstone.
Or a river called the Trident (for it splits into 3 branches reminiscent of a fork or trident)
Or a mountain(range) called the ''Mother of Mountains'' or the Frostfangs.
Such names are cool and make it less confusing and more realistic.

Now, if a fantasy word would contain only such, words containing real words, that'd be a bit lame.
But now look at Essos: Volantis, Meereen, Qarth, The Rhoyne, Krazaaj Zasqa.
and tons more.
martin also combined those mythic, creative names with the ''faraway lands'' or the lands outside of where the action takes place,
making it even more exiting. You'd wanna know more about those weird lands with those strange cultures and animals and Gods.

Lets say you got names like Yaratze.
It's a river for example.
And they travelled from Jugukuuluu(estonian-ish words, check out that language man) across the Toaitatar Plains toward the Yaratze.
To me (and many other readers) its just kinda meh.
it doesnt tell the reader anything, unless youre gonna explain the reason (if there is one) behind it. not only does that make it more boring
and slow, it's also gonna haunt you. And if there's translation for it because they have their own language, well, nice, but still. Keep it a bit down.
And it could go outta control, cuz creating your own language aint easy)

I'm a great fan of geographical names that got a ''realistic'' naming.
The Sloshing Snake or (got's) Blackwater Rush say alot more than the ''Yaratze''
Might be hard at words but eventually creative names come rolling out.
But don't completely leave the fantasy namings out.
I also got this part in my world where the namings are fantasy like, with exception of many geographical names.
What I also tend to do, as it makes it even more realistic: if you have a kingdom where they speak this language, have this culture, don't
create the names in such ways that they are completely different)

Like the town called Gossgaram is nearby Uilyakilithix.
Cmon guyssss.
If it was Gossgaram is near Motuggan, that's better.
I'd save that other name for another land, far away.
It gives the reader a sense that there's this culture, with similar names and ****.
In Greece, one island called Lesbos, the other one Mykonos, Hydra, Ikaria, Ios.
Like, oooh look. thats typically Greek.
You'd want that in your story too i guess?
if youre a fan of worldbuilding its pretty much a must imo.
I've got this desert region (although currently under occupation by a neighbouring empire) where many
towns and cities have the z and us and y in them.
Kayunus, Kososur, Talitaker.
Another region might have many names like Hrasar'Ta, H'ururge or whatever ****.

One name I liked alot was the Spine of the World, a mountain range, (forgot what series)
It's really creative yet gives a realistic feeling.
It tells you that its certainly a major mountain range, like the biggest of the world.
And probably very steep, theories and imaginations come to mind.
Whereas if it were called the T'aalam Mountains or simply he T'aalamis.
Its your own call, but the latter one is much...less memorable and interesting.

So just keep your namings and **** mixed and ordered.