How can i keep the dust away? i dust all the time and it always ends up back within a couple hours?

i dust every couple weeks but i feel like its just pointless! I will dust and wipe everything done and it will be nice and clean il come back couple hours latter and there is dust there, not much but still a little bit. i use Ajax spray and wipe and windex for the windows and mirrors i use a tea towel then wipe it down with paper towels after. does anybody know of something quick and easy or something please!!! i am having a baby soon and dont want everything dusty when he comes!!