I use standard Bar Keepers Friend (oxalic acid) often for minor rust on my kitchen knives. This is what I use most of the time, in part because I have it stored under the sink close by.
I sometimes will use a magic eraser type sponge (melamine foam) because... I have a big bag of generic ones to use up. (I don't recall the hardness of the melamine compared to steels though... I know it is not hard enough to scratch most glass... It might be hard enough to scratch steels.)
Flitz, as Skyfish0 suggested, is almost certainly a better recommendation, especially if the metal is already polished.