In a small bowl, whisk together ½ cup canola oil, 1 packet ranch dressing mix, and 1 Tbsp crushed red pepper until well combined.
Place 1 box (12.4 oz) Cheez-Its and 6 oz pretzel twists in a large zip-top bag. If needed, divide the mixture between 2 bags.
Pour the oil and seasoning mixture over the Cheez-Its and pretzels in the bag.
Seal the bag tightly, leaving a small amount of air inside to help the crackers move around more easily.
Shake the bag thoroughly until the Cheez-Its and pretzels are evenly coated with the seasoning mixture.
Serve immediately or allow the mixture to sit for 10-15 minutes before serving for even more flavor.
Notes
I find that it's best to leave some air in the bag when sealing as it allows the crackers to move more easily around the bag and get coated easier with the seasoning mixture. Store the leftovers in an air tight container or bag at room temperature for up to 1 week or you can refrigerate this mixture for up to 2 weeks.