When it comes to fool-proof protection from insects a physical barrier is your best option. Insect nets create an environment that allows you get on with your day or night, whilst those annoying insects watch from afar.
Insect nets are usually made of a dark material to improve visibility through the net and feature small enough holes to stop most insects. The main exception is the midge which required a very fine mesh with holes less than 1mm.
If you don't want to smother yourself in DEET or any other insect repellant claiming to keep these flying insects at arm's length, then get yourself an insect net to sleep under, or a screen room to dine and relax in around your campsite.