DIRECT TO GRANADA

Since Ryanair pulled out of Granada there are not many direct  international flights to Granada.

There is still a direct flight from Paris to Granada with Vueling
Info here
Vueling 


If you go with Vueling to Granada via Barcelona there are plenty of possibilities you can even fly from Moscow, Edinburgh, Brussels, Milan etc.
A flight from Amsterdam via Barcelona would cost 104 euros.

There are indirect flights with Iberia via Madrid or Barcelona.
Iberia


FLY TO MALAGA THEN BUS TO GRANADA
If you want a very large range of possibilities and cheap flights it is best to fly to Malaga.

The best website I have found so far is SKYSCANNER
[html]SKYSCANNER.com[/html]
There are loads of flights from all over Europe.
For example a flight from Copenhagen would cost 65 euros.

Do a search with OMIO 

For fast results go here and do a search

https://infoaboutspain.com/article/omio

The easiest way to Granada from Malaga is by bus.
There is a bus stop from within Malaga airport which takes you to the "estación de autobuses" (the bus station)
You can either buy a ticket at the station or buy one online at
https://alsa.es

It takes about 90 minutes.

Once at the Granada bus station it takes about 18 minutes into the very centre of Granada by bus
More info here
https://granadamap.com/bus/index.htm