I always take glucose tabs. Always the same brand (Dextro Energy Classic) and always the same rules:
70 = 1 tab (5g carbs, not enough but I will hit 90)
69-40 = 3 tabs (15g carbs)
40-30 = 5 tabs (20g carbs)
20-30 = 6 tabs (30g carbs)
If I am physically active I eat an additional tab. If I am doing some sort of sports I will drink an additional juice (200ml or more).
If I am unsure or confused by the low I always eat 3 tabs. I always cut 3 tabs from the paper package so I can not get confused about the counting - being low and counting can be challenging. The glucose tabs are quickly absorbed and I know my reaction to them very well. This gives me a high chance to hit the target range afterwards.
With glucose tabs I can manage situations like having a low directly before lunch and eating a high carb menu for lunch. Tabs first, then the meal and after that the injection reduced by a number of compensation units to cope with the low starting point (actually I use a formula for that). Being low 15 to 20 minutes before and then applying the next shot of NovoRapid needs some trust and I can derive that from the reliability of the glucose tabs.