And any other tips that people have found for helping reduce their blood sugar levels (slightly) due to change in diet or whatever
If you're not trying it already, pre-bolusing is well worth it, injecting before a meal to give the insulin time to get to work, before hitting it with food. That way, the food is meeting already active insulin so it's more of a level playing field, instead of the insulin playing catch up.
Timing varies between people, 20 to 30 mins is quite common, but it does need experimenting with, and will often vary depending on whether you're on an upward or downward trend, the gi of the food, the order that "faster" carb components in the meal are eaten, the general macro composition of the meal overall, and general sensitivity to insulin in the last day or two.
It can make a significant difference - I could eat a 50 to 70g meal and end up well above 10 for an uncomfortable period of time if I inject at first bite, but if I pre-bolus the same meal about 20 to 30 mins, it'll frequently not go above 7 to 8.
Sugar Surfing by Stephen Ponder covers the topic very well, although it's more aimed at people using cgm (which is well worth using, it's influenced my a1c hugely).
Sugar Surfing also says don't be shy of inter-meal corrections if the trend is going obviously out of line, but, again, that can be difficult to be confident about without cgm
Maybe also re-think ratios. Many of us get caught up in thinking 1u to 10g is set in stone (hcps can be quite strident about that), but it's just a general starting point, and there is nothing at all wrong with playing it differently. 1 to 7 seems to work for me pretty well, but again, it's entirely individual.
I suppose the big question is what do we mean by low carb? Many of my meals are around the 50 to 70g mark, with a fair number of 80 to 100g ones. Low carbers might look askance at those numbers, but I don't think 50 to 70 per meal is excessive, nothing which pre-bolusing can't handle, and, to be honest, the 80 to 100g ones are generally over a few courses, so nothing a bit of split-bolus won't handle depending on how long I'm taking to eat it.