Alright, been there and back, here's some recommendations that I was able to take away.
I made the mistake of going here too late in my trip and not having enough free time to browse leisurely. Most stores here are open from 12-8. There are a few nice jewelry stores and clothing stores, however these mostly seem to cater to women. There are also a few restaurants and galleries as well as a sake lounge. It also has a very good location, being located close to Wan Chai/Central although some paths leading to it involve climbing steep streets and stairs.
The one store here that stood out to me was Harrison Wong. Really excellent local designer that had a bunch of items on 50% off sale out the front - most stores seem to occupy a single room plus the balcony space in front - with more items in the main store. The website will explain better than I can, but many of the items available had unique features to make them interesting enough to stand out, such as textured or embossed fabric, while still being on classic, reasonable safe base silhouettes. There were some really nice jackets and pants, but I have already overloaded my wardrobe on outerwear and wasn't a fan of the cropped look of most of the trousers, so I settled for just a plain hoodie that features wide ribbon drawstrings and buttoned sides. Unfortunately, the brand seems to have no online store, though this makes them feel a bit rarer, only being available in Hong Kong. There is also a cheaper diffiusion line that more or less has the same concept. Both seem to range from about 300 HKD+, so was nice and affordable for someone with less money to throw around like me. There were also a few runway jackets on the sale rack out front. Would definitely recommend checking out. Website http://www.harrisonwong.com/
These places are always great but the hovery sales assistants make me a bit uncomfortable, but that's pretty standard for these types of stores. Not much to say apart from that the ones in Central and Causeway Bay were the go-to ones and enjoyable to browse. Sales assistants were dressed better at the Central one I think.
These were great to look through and try on a bunch of stuff that I normally wouldn't have access to at home. There's a pretty limited amount of information online about them, but I was able to locate two; one in Silvercord shopping mall - level 3 in the corner - and one in Citygate outlets. There is also one on the south side of Hong Kong Island, but I didn't go to that one. Items are discounted from 20%-80% off, though most discounts seemed to be about 50 or 60%. It's worth double checking the price with the numerous sales assistants wandering around the store as there are usually additional discounts that aren't signposted anywhere.
The citygate outlets one offered what I believe to be local streetwear brands such as 5cm, as well as some United Arrows, Neighborhood, Wtaps, Bape and Izzue. There were ladies items in the front, but I didn't really look through them. There was also a variety of shoes at the back, but nothing really seemed interesting enough to be worthwhile. I got a really nice UA Monkey Time reversible sukajan for ~800 HKD discounted from ~2700 HKD, despite the listed price being only 50% off.
The Silvercord outlet was significantly better, featuring items from various CDG lines (Junya, eYe, Homme+, shirt etc), Julius, Ann D, Uniform Experiment, Hysteric Glamour, as well as some others like 424, Stampd, Roarguns, Vanquish, Alexander Wang, MMM etc. I even managed to find some Rebuild by Needles jeans but didn't end up buying them. I'm having a mental block as I write this and am struggling to remember too much of what else they had but I've tried to write what I could. There was also a smaller variety of men's shoes and a wider variety of women's, but what was there was quite nice, even were some geothrashers.
I was traveling with other people so wasn't able to eat everywhere that I wanted to. Here's what I can say;
Fu Sing - Got this recommendation from the eater guide (https://www.eater.com/maps/best-hong-kong-restaurants). Made a reservation earlier in the day to go to dinner at 7pm. When we got there, there were only 2 other tables occupied, although the waiters did set up some extra small tables during the meal. Upon asking to order the baked barbecue pork buns, we were told they were only available during lunch, which I was pretty disappointed about. The rest of the meal was unremarkable and overpriced, although the pork that we did order was nice.
Top Blade Steak Lab - Went here on my last night here and was pleasantly surprised. They had a limited menu and I don't like steak, so I went with the chopped meat burger and was really happy with it. They have an all you can eat chips policy where they will regularly come around to all the tables with a big bowl of freshly cooked fries and top you up if you want them to. The dirty lemonade was really good; it was sour and had a nice punch to it. Would go there again.
Hoi On Cafe - Went here for breakfast twice, really enjoyed it. Not too much to say apart from that it was cheap and good. Their breakfasts are available before 11am and some of their specialty items are only available at 2:30pm or on Saturday.
That's all I feel like writing for now, I'm not really a bar or nightlife person so I can't really comment on that. Wandering the streets is a more enjoyable way to see the city overall I think, particularly getting lost and finding some nice places to eat is pretty fun. I tried to find the mall that liamb----ford described but wasn't able to.