Keep dried chips in a cool environment. The best way to extend the shelf life of homemade dried shrimp chips is by keeping them in a cool, dark environment. A few options include the cupboard or pantry. They should not sit in a sunny spot in the kitchen or in a humid environment.
Fry in neutral oil. It's necessary to fry shrimp chips in a neutral oil like canola or peanut to let their flavor shine through. Using a stronger-tasting oil (like sesame oil) will change the flavor of the chips, and you may not get the subtle sweetness typically found in prawn crackers.
Use a thermometer for the oil. While you can test the oil temperature with a dried chip (as noted above), using a thermometer is best. That way, you know if the oil is too hot or cold. Aim for 350F for the best results.
Only fry what you can eat in a few days. Once fried, shrimp chips only stay crunchy for a few days. Don't try to fry too many at once. Instead, only fry what you can eat the same day (or within the next few days).