Always look for opportunities to create striped candies, especially horizontal striped candies. Vertical striped candies are mostly not recommended, unless you combine it with another striped candy or a wrapped candy.
A colour bomb + colour bomb combo is very helpful in this level, as it takes a layer of frosting off. However, this opportunity is extremely rare. So if there are any opportunities, take it.
A colour bomb + striped candy combo is also useful. However, it may turn some candies into vertical striped candies.
As there are only three columns available for combinations and the conveyor belts mostly exclude prior planning, you are blatantly dependent on what's coming. So, good luck and be patient.