The reality is that any fish in a river close by Christchurch is getting a hammering thanks to YouTube. In addition, you have the environmental factors coming into play, so the fish numbers are well down. Where you used to get a 10 fish day on one of our spring creeks - now any fish landed is a great day.
I prefer to fish during the day, as that suits my preferred method of sight fishing. Prospecting a pool (blind nymphing a run or pool) is no longer worthwhile, so you have to put on the best polaroids you can afford and go slowly looking for a fish. Mayfly and Caddis hatches have been non-existent so far this spring, so fish are not out on the feed. Thankfully we can look forward to some willow-grub action soon, which will shift the advantage to the angler.
It feels a bit early for an evening hatch of mayfly or caddis, but they will happen and once they do any flat stretch on the Waimak in the evening is worth a look. Same on the larger rivers around the region. I was out last night trying to recover a jersey I lost out fishing Sunday. Didn't see a rise or a fish. Sunday they were leaping to Damsels flying or lifting for mayfly and caddis emerger’s, but bugger all about.
Late spring you can get some good action in all the local rivers in the evening when brown beetles start to hatch – the starlings have wrecked a patch in my lawn, so they are not far off flying. Same for cicada’s too – our local fish key onto these once they start to move.
Now that the high country lakes are open just wander the edge and offer something that looks like food – a soft hackle looks like a caddis and does it for me most days.
Knowing what it is that you are seeing hatching – and fish feeding on, then matching the hatch is part of the allure of fly fishing. There are plenty of very good books on the subject in the library if you haven't already accessed that resource. BTW: Tying that bug is just the start of a very slippery downhill slope
Sounds like you need to get to know a few other fisher people, and just generally ask questions, and then get out and observe. You could start with the team at Fisherman’s Loft as they are not shy of good advice - they have a young lady part timer. Joining a club is not for everyone, so no shameless plug for the https://canterburyanglersclub.org.nz/
- it depends on what you want to get out of one. We have a few ladies that fish (both fly and spin), but you would find any of the blokes at a club night helpful too. We do have an under-utilised library full of NZ fishing books BTW... And there is also the Canterbury Fly Fishing Club - they have some very capable Lady anglers too.