This is what I do ...........
I apply a layer of bond before applying my tip.........
it provides a good base for tip adhesion........
Bond is a very thin EC resin and will penetrate the nail plate, so when you apply the tip with EC resin or gelbond you will have the perfect bond........greater adhesion............
As for a layer of gel before tip application..........
When I was taught over 10 years ago, they taught us that too..... the reason being........ new Tech, blending tips, it gave the new tech a safety net for tip blending..............The layer that was pre- applied was a very very thin one.........Or if it was an uneven nailplate to even it out with gel......these where the days before gelbond was invented........
But if you are best friends with your file, you will never file on the natural nail anyway................Pre blending is also brill.......if the natural nail allows you too.......... i.e not bitten to the elbows or mishaped so that you need the sidewalls of the tip to re-enforce or form the nail structure............