dollar general and the png boosters

how should we ensure we get the $5 off next purchase when we spend $20 on png products at dollar general for tomorrow with the saturday $5 off $25? i have my list with $21 worth of applicable png items and they have coupons and i added a 2/$5 deal to my cart also with some coupons so i can hit the $25… would this work? i have done a booster before but i was following someone so im not sure if me getting to the $21 will work!