Day trip to Shenzhen from Hong Kong

Summary
Shenzhen is worth a visit if spending more than a couple of weeks in Hong Kong and the surrounding area, especially for the view from the skyscrapers to see the sharp contrast between the rice fields of northern Hong Kong and the booming glass, steel and concrete structures of Shenzhen and generally its super futurisic feel at times. The Dafen Oil Painting village and Luohu Commercial City will all of its fake handbags etc are also worth a trip
But to be honest I wouldn’t prioritise it over any of the classic or hidden highlights of Hong Kong, or over a day-trip to Macau. For details on these see, my tips on the entries for 2 days for the famous highlights of Hong Kong, 2 days hidden highlights of Hong Kong, and a Day trip to Macau from Hong Kong
highlights

1. The view down on the border with Hong Kong from one of the tall buildings, such KK100, to see the sharp contrast between the rice fields of northern Hong Kong and the booming glass, steel and concrete structures of Shenzhen

2. The Dafen Oil Painting Village, which is surprisingly atmospheric with its 600+ artistic stores churning out copies amongst the cute alleyways

3. The Luohu Commercial City on the border entrance you will most likely enter from, which is a whole world of fake designer clothes, bags, and just about anything

4. Generally walking around the place as you get impressed by just how futuristic Shenzhen is. Its doubly strange as you realise you are getting this feeling in comparison to Hong Kong, one of the most futuristic and developed cities in the world
Experiences nearby

The below map shows experiences nearby with a colour that reflect the Overall Score of those experiences
Score Detail
Background - how many times have you asked someone what a travel experience was like and the response was "amazing" or "awesome"? That response is nice to know, but it makes it hard to differentiate that experience compared to others. That is exactly what these scores are trying to do - differentiate the experience by giving a score out of 10 based on 6 categories and then giving an overall experience score
This overall experience score is calculated by: take the highest of the "Culture" or "Nature" score (1-10) + "Fun factor" (1-10) + "Avoiding the crowds" (1-10) + highest of the "Unique" or "World Famous score" (1-10). Then convert into a score out of 100
Extra detail - the logic being that I find all of the 6 individual scores important, but I don't want to mark an experience down just because it doesn't cover both "Culture" and "Nature", or because it isn't both "World Famous" and "Unique". Take the examples of Safari in The Serengeti and walking through Rome - they both appeal at opposite ends of the nature / culture spectrum, and you can have a fantastic time without needing to appeal to both sides. So, their overall scores aren't penalized for their lack of one or the other, and I've done the same for "World Famous" vs "Unique". But . . . I do think that the "Fun factor" of an experience is important, irrelevant of other factors, and so is "Avoiding the Crowds" (or where there are crowds that add to the experience). So, both of these scores are standalone