Another oldie but goodie pattern is the use of plaids. You do not need to go overkill and have plaid in every visible space, but instead infuse the bold pattern in little accents and details.
Love the below idea of bringing in the pattern on the base level of this cake below or you can even just use the design on the cake stand.
Source: Posta Bella
Use it on your cookies, cupcakes or petit fours sporadically.
Source: Baked Ideas
Loving the plaid bows on these gifts.
Source Favor Studio