I've got my save setup, and will be doing run practice in a few days. Anything I should practice beforehand/ tips to remember?

The big thing I would recommend is to check out the guide section on the left. Both Lilly and Key have written good guides for both of the main categories, NG+ and Any% depending on which you want to do (Quick link here: https://www.speedrun.com/Yakuza_Kiwami/guides ) Lilly's guide in particular is super comprehensive and worth looking at even if you plan to run NG+.

Big thing I would recommend is learn which cutscenes are skippable and which aren't - whilst also knowing the best route from A to B with Taxi fast travel etc. Again Lilly's guide is really good for this

One thing to note about my guide for Any% is, it isn't completely updated with the newer shotgun strats for the end game. But I'd honestly recommend the older route first if only so you understand enemy placement. You can always watch the video for the WR if you really wanted to use them straight away although that run was honestly a test run that worked out.

I will get around to updating the guide at some point, I have just been taking a break from serious speedruns for a little while due to health issues.

I had used the NG+ guide to get my inventory setup. The save is there, and the run seems fairly straight forward: use dragon fighting style for most of the run, shotgun the crap out of everything, and avoid majima as much as possible.