I tilt my head right back so my face is almost horizontal and then drop a drop of the eye drops into the corner of each eye nearest my nose. Practice makes perfect.
Viscotears are a different matter, gave up with them not just because of the difficulty of administering them but they make my vision too cloudy.
I’ve recently bought some eye spray from Asda opticians, own brand stuff, which is very easy to use, effective, and a lot cheaper than the branded spray. You spray it onto closed eyes and it works it’s way into your eyes.