As a d4 player, I've learned to start with 1.Nf3 and transpose into d4 openings. The advantage of this strategy is its great flexibility and also psychological confusion for Black.
Not knowing what White would do after 1.Nf3 d5, Black often plays some unusually bad moves in the very beginning of the game. Something like 1.Nf3 d5 2.d4 e5, 1.Nf3 d5 2.d4 c5, 1. Nf3 d5 2. d4 Bf5 and 1. Nf3 d5 2. d4 Nf6 3. c4 g6.
I was facing a strong player in this game, he would never have played 1. d4 d5 2. Nf3 e5 because it looks unsound. But the 1.Nf3 move order has a lot of confusing power. It gives Black many options but most of them are bad. I strongly recommend d4 players to learn the 1.Nf3 transposition, it avoids many strong Black defenses like the Nimzo-Indian and Grunfeld and tricky gambits like the Old Benoni and Budapest Gambit.