yes you can definitely do that. the only problem is that "luxury towels uk" is not a real phrase like "web conferencing services" which fits into a sentence and has good search volume.
"web conferencing" and "conferencing services"
"luxury towels" might be but "towels uk" is probably pretty weak
So basically you would need to incude instances of the phrase in your content "Shop our store for a wide variety of luxury towels uk and see our quality" it doesn't read proper. I would rethink the keywords.
Also, yes include the singular as well as the plural and variations and synonyms. Put similar words on the page that Google knows are related to towels such as bath, beach, microfiber, cotton etc and you can rank for long tail searches as well.