The objective is to be able to play with them, and the only way to acheive that is protect their feelings. In a decade of experience in frequently recruiting new players to Dominion, one of my findings was that I have to use a handicap method that lets them distract themselves from the handicap so they can forget it. If they see me pass on several of the opening turns, it drives it home too much.
If I start with a weakened starting deck, then after the game, they take joy in their victory and want to play a second game-- unless a smartass with poor social skills points out that I started the game with four Curses, three Coppers, and three Estates. Then the enthusiasm for playing a second game immediately wanes. A good handicap method is one which politely crawls into a memory hole.