Is there a best way?

The "best way" is to pick out the major beats of the story and play up those.
An animated film has to have certain dramatic points reached at certain times, usually to fit within the running time of the film--a comic book/graphic novel doesn't necessarily abide by that.
Since a page is read at whatever rate the reader chooses, the pacing of a printed story can be quite different from a movie.
That means that slow or fast paced sequences of the story can be different from when read to when seen in cinema. That also means that certain details, elements of the story or even whole sequences of the printed story may need to be altered, abridged, edited down, or even excised completely to work in cinema.

So, again, the work of adaptation has to look at the major thrusts of the story, the key points that need to be delivered and address those. That could mean that something that may have been given very little page-time in prose might need to be embellished in cinema. Again, that changes the written work.
As long as the main ideas and messages remain, there's every reason the story can translate from a graphic novel to the movie screen.

It doesn't matter if the printed material is a straight written prose story, or a graphic novel--this is why a lot of movie-goers "who also read the book" often complain about how the movie is different from the book.
What they see in their mind's-eye may PLAY like a movie, but the reader doesn't realize that they are timing out those mental visuals at their own discretion, with all the luxuries of time that cinema cannot always accommodate.

A graphic novel has visual panels with it, and some people believe that is the equivalent of having a storyboard right there.

Uh-uh, not so fast.
Comic book panels work, in a distantly related fashion more to a beat board, not a storyboard specifically. yes, a comic page can show specific action more so than the generalized staging of a beat board proper, BUT there's still the absence of proper shots staged for the cinematic screen, camera moves called for and worked out and dialogue cued to specifically broken-down poses. A storyboard is then, quite a different animal than a comic book or graphic novel, because the storyboard is quite literally the blueprint for the film.

Outside of that......there's plenty of different ways to interpret a graphic novel into cinematic form.

First of all, Great comments Ken.

I keep lurking around the site and I receive a notification whenever someone posts.

To answer the question. You can "track" the story and see where the highs and the lows are as far as pacing. You can draw a graph to indicate the story path.

Ask yourself - "How does the story build- and where?" Where are the lows - how can you bring the lows up or eliminate them?

You can put the information about each sequence on post-its and put them on a wall.

You can also shoot the graphic novel like an animatic or leika reel and see how the pacing works.

Most Japanese animations are adopted by graphic novels,I think you can search some articles about this.

I was one of the people you mentioned as believing the comic/graphic novel was equal to a storyboard. Thank you for correcting that misconception.

So, now if I understand things correctly a graphic novel/comic would be, at best, something to base the storyboard on.

Yes.

Just remember that the panels on a printed page do not necessarily correlate to the cinematic screen.
A comicbook page can have dynamic framing--meaning the panels can be almost any shape and proportion.
A cinematic screen has static framing, in that its aspect ratio is pretty much locked down. You can split-screen in cinema, and you can frame a shot so that its not the set aspect ratio per se--such as a panoramic widescreen shot with more black spaces on the top and bottom, or a vertical framed shot with the backs on the side...........BUT, the usage of such framing is very rare.
The context and ambience of a unusually framed shot in a printed comic may be part of the storytelling thrust of that panel, something that may not translate properly to cinema without additional information being imparted.
A strong visual image in a comic may be strong because it's been framed to only include specific visuals in a specific way. A cinematic shot may not be able to be framed the same way, and so may have to include added elements ( such as backgrounds) that can alter the impact of the shot.
Batman crouching and growling in a comic book panel can be framed just around the drawing of Batman (because the panel can be any shape), and thus hit certain emotional notes.
In cinema, Batman might be hitting the same stance and expression, but the frame is wider ( because of the aspect ratio of the shot) and this includes background elements, and perhaps lighting differences that alter those emotional notes. The cinematic shot of this example , tackled the same way as the comic may lose much of it's impact because of the extraneous information in the shot. Furthermore, just staging it tighter to exclude that extra information may invoke completely unexpected reactions because you may then have a snarling Batman face filling the screen instead. It could read as unintentionally funny, for example.

This is why a direct translation from comic book to cinematic storyboard is difficult to pull off, and the process has to be interpretive before anything else. This is why adapting a graphic novel to screen requires the imagery to be largely re-thought (and vice versa, indeed) and even staged differently to try and say many of the same things in both.

Make sense??