Comparisons with that other great modern mythology, namely The Lord of the Rings, are somewhat commonplace, undoubtedly because both have sword fights, wizards and good versus evil. But really, beyond that, the comparison falls apart pretty fast, which shouldn’t be surprising to anyone who has been paying attention to the kind of sources Lucas generally drew on for his space fantasy.
That having been said, here’s a section from Tolkien’s The Hobbit:
“Good morning!" said Bilbo, and he meant it. The sun was shining, and the grass was very green. But Gandalf looked at him from under long bushy eyebrows that stuck out farther than the brim of his shady hat.
” What do you mean?“ he said. ”Do you wish me a good morning, or mean that it is a good morning whether I want it or not; or that you feel good this morning; or that it is a morning to be good on?"
”All of them at once," said Bilbo. 
And here’s a section from the third draft of Star Wars :
A huge menacing shadow on the canyon wall gives way to a shabby old desert rat of a man, who appears to be at least seventy years old. His ancient leathery face, cracked and weathered by exotic climates, is set off by dark, penetrating eyes, and a scraggly white beard. BEN KENOBI squints his eyes as he scrutinizes Luke in his predicament.
BEN: Good morning!
LUKE: What do you mean, ‘good morning’? Do you mean that it is a good morning for you, or do you wish me a good morning, although it is obvious I’m not having one, or do you find that mornings in general are good?
BEN: All of them altogether. You seem to have gotten yourself into a fine mess! What happened?
The wizened old man begins to giggle like a child, putting his frail hand to his mouth in a vain attempt to contain himself. Luke becomes annoyed. [Scene 39, 2]
It’s a somewhat odd addition so late in the writing process, undoubtedly springing out of Lucas’s further efforts to scavenge ideas as fuel for his own writing. And while it doesn’t feel entirely out of place next to the Kurosawa bits, it didn’t survive more than this one draft.
There continues to be plenty of speculation about what other influences Tolkien’s writings might have had on Star Wars, but at the end of the day it’s worth keeping in mind that most of Lucas’s inspiration came from comics, serials and movies; not thousand page books. And while there is certainly some comparisons to be made in terms of Tolkien and Lucas as world builders, there isn’t quite enough hard evidence to suggest that Lucas took anything but a passing bit of inspiration from Tolkien’s worlds or even his approach (though over the decades they would perhaps end up spending nearly as much time on their respective sagas).
That Gandalf and Obi-Wan share traits is perhaps better written off to the fact that both draw on the stereotypical wizard of fairytales and fantasy. Granted, Tolkien planted the seed for all modern fantasy with The Lord of the Rings, and so Gandalf is in many ways the stereotypical wizard because he was the first wizard; but he himself was based in large part on Merlin of the Arthurian legends.
And sure, Bilbo’s blade Sting (which is later gifted to Frodo) glows blue when orcs are near, but is that the sort of detail that might birth something like the lightsaber? It’s easy to think so, given that Sting itself is a rare blade in the world of Arda, much like lightsabers were rare in Star Wars. But it’s worth remembering that in the early drafts, lightsabers, or lazer swords as they were known (and as Lucas continues to refer to them) were weapons as common as blasters. So it seems just as likely that Lucas simple carried over a staple from Kurosawa’s jidai-geki, Flash Gordon and similar adventure films in the form of the steel sword, and science fiction-fied it by having the blade be made from laser. This is quite similar to how ray guns became the futuristic version of ballistic weapons in early science fiction like War of the Worlds, and eventually grew into a staple of the genre (see Forbidden Planet).
There’s no arguing that Lucas eventually caught on to the idea of casting himself as a student of myth and fairytales in the same way that Tolkien had been, though the two mens pedigree is inarguably extensively different. Tolkien was an english professor intimately familiar with the very mythology and fairytales of Anglo-Saxon, Germanic and Nordic descent, the likes of Beowulf, the Arthurian legends and Völsungasaga that he would later draw on to a great extent for his own ‘british mythology’. Furthermore he was a scholar of language, which would provide a solid (and extensive) foundation for the cultures and races of Middle Earth.
Lucas on the other hand had an interesting and something akin to passing knowledge of mythology and anthropology from college. He had probably read some of Joseph Campbell’s writings, though the later portrayal of him as Campbell’s best student was, at least in the beginning, less than accurate, and his approach to mythology building was not one based in academia, as was Tolkien’s, but one based in the world of pop culture.
When Star Wars was first released, Lucas certainly talked about fairytales and mythology, though not more than he might have learned from having watched Sergio Leone and The Wizard of Oz from afar. But as the film exploded in popularity, the media hung on his every word looking for an explanation as to why this seemingly innocent popcorn fare so thoroughly gripped its audience. While Star Wars isn’t devoid of a conscious effort to create a fairytale-like story, it has more in common with The Wizard of Oz than it does with The Golden Bough. It’s noteworthy the more interviews Lucas did, and the larger Star Wars became, the more the academic angle of Star Wars’s mythopoeia was played up, while the actual influences often played down (and some never mentioned, even in passing).
Finally of course, there’s the matter of the climactic titles of both series. The Return of the King and The Return of the Jedi.
J.R.R. Tolkien. The Hobbit. George Allen & Unwin, 1937.
George Lucas. The Star Wars - From the Adventures of Luke Starkiller. Lucasfilm Ltd, August 1st, 1975.