It is well-documented and often-cited that Tolkien began creating his major artificial languages, Quenya and Sindarin, in order to emulate his aurally favorite languages, Finnish and Welsh. Q and S were certainly a labor of love as he worked on them all his life, for about 60 years. He worked a lot refining them and also inventing the "historical" etymology of words and names, a derivational system with rules, roots and elements and their cognates among the Elf languages, showing a fictional interrelation between them.
An obscure language that was, I guess, also a labor of love, was Taliska, one of the languages of the Edain, which reportedly was based on Gothic or some Germanic languages; as in his early legendarium the Edain were he fictional ancestors of modern humans, perhaps in his mind Taliska was the fictional origin of the germanic languages.
Although I am not aware if Tolkien ws fond of the semitic languages at all, he did experiment with them, giving Adunaic and Dwarvish a "semitic flavor" and structure. Adunaic belongs to a different stage of development (1940s) and obviously he had abandoned the idea of Taliska by then. I am not sure why he wanted to have the Numenoreans speaking a quasi-semitic languages but he did note that the Dwarves have something in common with the Jews.
While writing LOTR, again in a later stage of his life and his subcreation (1950s), he got the idea of the Common Speech of the Westlands, which is a direct descendant of the Adunaic language, similar to how classical Latin evolved to the vulgar Latin as a common european speech. He did maintain his concepts of Adunaic while writing LOTR as some Adunaic names are seen there.
As for Orkish, he deliberately made it ugly.
During his writing, he entertained with the idea that the text and the names are a direct "translation" from Westron to English. As the Westlands had other languages related to Westron, he "translated" them into other germanic languages (Old English, Gothic, Norse); he also used Celtic elements and names to show more distant to Westron languages. All this creates an elaborate "translation" system. He showed this with the examples of the names Smaug (Norse), Smeagol (Old English) and the hobbitish word "smial" (invented, but derived from Old English), all connected to a germanic word for "burrowing".
A sample of genuine "untranslated" Westron words can be seen here: https://folk.uib.no/hnohf/westron.htm
And now my question: Do you think that Tolkien had anythng in mind while creating the Westron words? Westron derives from Adunaic which has a quasi-semitic structure but this is not apparent in the Westron corpus. Also, what do you think is the "character" of Westron? Considering that Tolkien paid so much attention in beauty of sounds, and the images that can be evoked by the shape of a name, he didn't seem to strive for beauty with words like "Suzat" (Westron name for the Shire), "kuduk" (hobbit), "Phurunargian" (Moria) or "Karningul" (Rivendell). It seems that he experimented with Taliska for a fictional ancestor of the germanic languages, so, considering Westron's cultural significance and ubiquiteness in Middle-earth during the Third Age, could it be considered a fictional ancestor of modern human languages, Indo-European for example? And since he liked so much playing with Elvish etymologies and connecting Elvish names to "Proto-Elvish" roots, did he ever played with the etymology of Westron words from Adunaic?
Personally, the only "character" I see in Westron is some "playful" mood in hobbitish names like "Bilba Labingi" (the genuine names of Bilbo Baggins), Tomba, Matta, Zaragamba etc. But other than that, it seems that his Westron creations were arbitrary, not based on any Adunaic derivation, real-life inspiration or even esthetic principle, which is curious for Tolkien, and such a significant language like Westron.
