I have been searching through the forum but I haven’t found much info on how to (if possible) increase dream vividness.
Except for the topic about cheese. 
The WBTB method is the best for inducing vivid dreams I think.
Hmm, WBTB is the method I’m practising, but my dreams are far from vivid.
You can try to give more attention and concentrate more on your senses, in the dream and IRL. Like look around during the day and try to notice as much detail as you can. Look at how the water sparkles in the sun, or things like that…
You could also try to demand/ask your dream for vividness. “Increase vividness!”, for example. But you might want to try to do that only with thought, because when I tried this I spoke it out loud and I think my lips moved (on my physical body, that is) and that woke me up… 
Haha, well it’s hard to demand for the dream to be more vivid when I’m far away from becoming Lucid in the first place, I figured it would be easier to become Lucid if the dream was abit more vivid.
If I ever remember something from my dreams where I am now it’s only small fragments, and it doesen’t feel like a dream I just had, it feels like a dream I had weeks ago.
oh, ok. my bad. Yeah, demanding vividness in a ND would be rather difficult. 
Try the attention thing then… I’ve been trying to pay more attention on my sense of touch and I have noticed it a bit in my dreams…
Keeping a DJ would help too, I don’t know if you do… it would increase your dream recall in quantity and quality (bigger fragments 
)
yea, the more dreams you recall, the more vivid they’ll be, probably