Totally agree on the lack of shadows and the "flat" effect. I've been playing around a bit. Also, I'm toying around with the possibility of adding some smoke in the foreground:



In my mind this is balancing a little bit the composition bringing color to some zones that were feeling pretty empty (compared with the rest of the piece) and also guiding the eye a little bit away of those bright magentas in the middle and closer to details like the dumpster. Maybe is too much tho, a contrapoint in this subject would be very useful. 

Special thanks to eishiya: I feel like thanks to your critique this piece is now in a whole new level (even tho still work in progress xD)

I'm bringing an update!



Definitely is darker and also more generally glowy. Thanks again for the tips and references. I'm going to be cleaning up A TON, but I'm feeling so much confident now.

Hey, thanks for the feedback and references.

I came up with a quick mockup for the lighting, I hope this is better now. I'm worried that maybe is too much now?



Thanks again, I really appreciate your time 

Note: I'm not really paying attention to misplaced pixels or color counting right now, only wanted to have an overall feeling on the lights

Hi there!

Recently I'm working on a piece that I'm liking a lot so far, but I'm kind of stuck trying to add some depth to the neon lights in the top part of it. I already added some reflections and highlights, which I like, but I also want to add a general glow to them.

This is my "best" attempt, which I don't like a lot:



I'm also attaching a version of the picture without the glow just in case someone wants to play a little bit with it and make some edits 



I will appreciate any tips and tricks that you guys have to glow up those cute neons!

Here's my main reference here (large image):

Spoiler
The point of view is not exactly the same, but is close.

I also tried with a hairstyle closer to the reference, which is darker and causes less troubles. But is less accurate with my actual recent look