Thanks for starting this interesting thread, which will probably mainly appeal to calm positional players...
Maybe I should mention that though the move order you suggest is mainly aimed to avoid the Budapest Gambit (1.d4 Nf6 2.c4 e5) and Albin's Counter Gambit (1.d4 d5 2.c4 e5), you can't avoid a gambit altogether: 1.d4 e5 is the Englund Gambit, but it has a very doubtful reputation. This goes to show that if your opponent desperately wants to play a gambit, there is nothing you can do to keep him from it. In such cases I would like to advise you to go with the popular rule: "Gambits are best refuted by accepting them!", especially when your opponent plays a line of doubtful merits.
Instead, I don't hold too much with playing passively. I think that after moves like 1.e3 or 1.a3 you can indeed keep your opponent from sacrificing a pawn for a few moves, but chances are that he will reach an active position he is very comfortable with nonetheless - only this time he didn't even have to sacrifice a pawn for it. 
Hello everyone!
Are you afraid of dangerous gambits? There is some ways to avoid them. I'm going to show you at least a couple of those. In this case we are playing with white pieces.
I can assure that it's not funny to face a dangerous gambit if you are playing in (over the board) OTB-competition when it's the last round of day and you are already tired.
First alternative way is this: 1. d4 + 2. Nf3
Second way to avoid gambits is to play peaceful moves like:
1. a3 or
1. e3.
Behemon - Paladin of Chess